So Stern has had issues with poor assembly of the wiring under the flipper plates on Spike2 machines for a while now. There's too much unnecessary wiring volume, zip ties are way too tight and unnecessary, and there's no protection for the wires as they come out from under the flipper plate. The result of this poor design is that as these machine age, vibration from the flipper plate and shaker motors saws through the wiring insulation either where they come out from under the flipper plate or where the zip ties are attached too tightly. Once that happens, the wire intermittently makes contact with the flipper plate as you play, causing a node board reset, which basically looks like the lights going out on part of the playfield, then all the inserts turning on and off, one after the other. Flippers go dead for a couple seconds while it resets, too.

Ideally, you want to make this fix under both flipper plates, but it's a royal pain, so I understand if you want to just do one if you're having the problem *right now*. To narrow down which plate has the short, concentrate on just flipping one flipper at a time repeatedly. You should see that the vibration of one flipper causes the reset much more often (or always). That is most-likely the one with the short.

Before you start you need to go to the hardware store and get some 1/4" inside diameter flexible tubing (3/16" outside diameter). This was 10 cents a foot at Ace Hardware here, cut to the length you need from the bulk rolls. I went for 10 feet because I was flush with cash and $1 wasn't going to scratch my fat stack that day. Plus, having had a lot of Spike machines, I knew this would not be the last machine needing the fix.

Now that you have your tubing, you also need:

1/4" nut driver (to remove flipper plate)
Hex wrench (to loosen nut on flipper pawl to release flipper shaft)
precision cutters (to cut the wiring to the correct size and remove the bad area with the short)
weller soldering iron and solder (hakko will do, too)
flat head screwdriver OR staple remover (to remove staples from the insulating fish paper)
stapler/upholstery stapler (to re-attach fish paper)

Wiring coming out from under the flipper plate shows rubbing through the insulation:
node_reset_fix-0 (resized).jpg

Use the 1/4" nut driver to remove the 8 screws holding the flipper plate to the playfield, then remove the flipper plate. You can see that the zip ties are too tight and will be unnecessary once the wires under the flipper plate are made the correct length
node_reset_fix-1 (resized).jpg

With the zip ties removed there's a LOT of extra wiring coming out from under the way-too-short piece of insulating fish paper.
node_reset_fix-2 (resized).jpg

Now you need to loosen the nut on the pawl holding the flipper shaft in place so you can slide the flipper out and release the plate from the playfield. Once you have the flipper shaft out, move the flipper plate to the side, and remove the fish paper staples and paper. There's too much wiring.
node_reset_fix-3 (resized).jpg

Cut 4 pieces of tubing with the precision cutter.
node_reset_fix-4 (resized).jpg

Unsolder the connections one at a time and cut the excess wire out (including the part that has rubbed through and is causing the short, then slide the tubing on and re-solder the wire. When you're done, it should all lay flat like this (I did zip tie the top two tubes together after I took this picture):
node_reset_fix-5 (resized).jpg

Put the fish paper back on and staple down. I used an upholstery stapler and it's not the most beautiful job. You can probably do better:
node_reset_fix-6 (resized).jpg

Put the flipper plate back on, re-install all the screws, and the re-install flipper bat and align. When you're done, the wires coming out of the flipper plate will now be protected by the tubing, and all the wiring under the plate will not be crushed by zip ties that can cut through the wiring, too. Node reset problem, solved.
node_reset_fix-7 (resized).jpg

If you want to have a roll of insulating fish paper on hand (I recommend it), you can get one pretty cheaply (less than $4) at digikey.com:
https://www.digikey.com/en/products/detail/gc-electronics/560/257752

All done with this project? Here's a couple other DIY guides I've made for newer Spike machines:

Are LED lights popping out of your spotlights (not just on Spike machines!)? Make sure they never fall out again:
https://pinside.com/pinball/forum/topic/fixing-led-bulbs-flashers-that-fall-out-of-spotlights#post-4402506

Have a Stern machine from KISS or after with the softer wood cabinet? Reinforce it to prevent a splitting cab:
https://pinside.com/pinball/forum/topic/reinforcing-stern-cabinet-legs-step-by-step

Want to have the option of operating the action button on your spike game with a foot pedal?
https://pinside.com/pinball/forum/topic/action-button-foot-pedal-for-bksor-godzilla-etc#post-6616394

Have an $80 alibaba hologram fan topper you want to cleanly power so it turns on and off with the machine? Do this:
https://pinside.com/pinball/forum/topic/hologram-fan-or-lightedpinballmods-power-fix#post-6241182

Are your Iron Maiden speakers crackling when you crank it up? Fix that with a cheap external amp:
https://pinside.com/pinball/forum/topic/replacing-on-board-amp-with-external-amp-for-iron-maiden

Add a working lockdown bar button to your Iron Maiden
https://pinside.com/pinball/forum/topic/iron-maiden-how-to-add-a-working-lockdown-bar-button

Deadpool Katana entrance protection:
https://pinside.com/pinball/forum/topic/protecting-katana-lane-entrance-from-playfield-damage

Is your Spike machine occasionally resetting during hectic play, torpedoing your high score runs? This guide to fixing it might be for you:
https://pinside.com/pinball/forum/topic/fixing-stern-reboots-on-spike

Do you have a WoZ ECLE and think it's too loud in a quiet room? Replace two fans and make it almost silent:
https://pinside.com/pinball/forum/topic/quieting-down-a-woz-ecle-machine

And here are some other plug and play mods you can just buy:
Iron Maiden Light Tree Mod for colored mode lights:
https://pinside.com/pinball/forum/topic/iron-maiden-colored-mode-lens-tree-mod

Metallica F-U-E-L lights bracket:
https://pinside.com/pinball/forum/topic/metallica-f-u-e-l-gauge-lens-bracket

ColorDMD gasket for Stern machines with the angled speaker panel:
https://pinside.com/pinball/forum/topic/colordmd-gasket-for-angled-stern-speaker-panels

That could work, too. But now that I've seen the huge amount of excess wiring under the fish paper, if I've got to take the thing apart, I'm going to clean it up with the tubing. It's not that much more work, and getting the plate off and removing the flipper, then putting it on and re-aligning the flipper is the pain.

And Stern hasn't adopted any positive change with a better wiring setup or longer fish paper under the flipper plate that extends past the edges of the flipper plate. I have a JP Prem that has a build date just weeks ago - same problem.

Yeah, my OCD will not allow that. But it is absolutely a way to fix the trouble spot at the edge of the flipper plate with way less effort.

This is a good time to mention that you can get a bulk roll of fish paper from digikey for less than $4. Nice to have on hand to cut pieces when you need them:

https://www.digikey.com/en/products/detail/gc-electronics/560/257752

Definitely a node board resetting. Do you have a node error in the system menu? If you run the node diagnostics, do you get an error?

Looks like it might be a switch short or the wiring under the flipper plate not having enough fish paper, causing a short. If you raise the right lower and upper flipper manually, does it cause the reset? If not, if you smack the playfield firmly with your hand in the center, does the vibration cause the reset?

Before removing the flipper plate(s), I would remove connector CN15 from Node 8 (that's the node board closest to the flippers) and see if it stops happening.