Personally it sounds like you may need to replace either your cabinet switches or your EOS switches. It sounds like the contacts on the switches are making contact a little bit, but they aren't allowing the full voltage to go to the coil. I would clean your contacts first, and if that doesn't fix your problem, I would definitely try changing out those switches. I hope this helps.

Have you rebuilt the flips? new sleeves, coil stops, bushings etc...? check the return springs?

it is helpful for you to list your location in your profile. that has a bearing on this response...

as humidity increases, wood gains thickness. that is, your playfield expands.

if you rebuilt your flippers in the winter, when there is less humidity, this may have some bearing on how flippers work in the summer.

The up and down movement of the flippers (not the rotation) will decrease in the summer. this can cause flippers to stick. if you rebuilt them in the winter and didn't leave adequate up and down movement, this will be a problem in the summer.

Sounds like worn flipper parts...replace plunger and links coil stops and sleeves and you should be good to go

If you have that much heat in the garage I would be concerned with the expansion and contraction going on the playfield plastics. Check for hairline cracks around the bolts and screws or warpage on areas like the slings. If its 95 outside its over a 100 in the garage. Your probably looking at a 30 to 40 degree swing each day-night in there.

Since you're in VA humidity is definitely something to think about. so in the summer, the playfield will swell a bit. when it hangs check for up and down play on the flipper bat. if there's none, then humidity is the issue. but hey that's an easy fix, just an adjustment.

An easy thing to check that may be binding is that the flipper bat still has a credit card thick gap between the bottom of the flipper bat and the bushing.

Classic symptoms of flippers installed to tightly down to the playfield. Not enough up and down play.
It shows mostly when the games are warmed up and played for a while, but in the heat and humidity probably worse.

^Could be your flipper bat is rubbing on the bushing... Make sure you have a sight gap between the flipper and the bushing(about the size of a credit card)

Rebuild the flippers with new coil stops and sleeves. Just google the machine manufacturers name and repair.
Search
Eg. Williams pinball repair.

Then go to rebuilding flippers section.

Loosen the allen screws from the flipper shaft under the playfield. Pull the flipper up so there is a tiny gap between it and the pf, line it up and tighten the screws. THis should prevent it from sticking the future. Like Homebrood said, classic flippers installed to tightly to playfield

Yup, that's what I would say.

Though people are recommending a credit card thickness, I generally go with a bit more play. Because where I live weather changes wood a lot between the seasons.

Before assuming they need adjusting, simply lift up on the flipper bat and check that there is a tiny bit of up and down movement. You should be able to feel a very slight movement. If it moves, they are not too tight and no need to adjust the gap.

yes true that can happen too. it causes the plunger to move at an angle through the coil sleeve, adding potential for binding.