Got a picture of the gap on the EOS switches just to confirm?

Try cleaning all those contacts really well as well as ajusting.

That's usually what it is but as you say it is weird that it's on all flippers. I just want to make double sure the EOS look right before getting weirder. Coils haven't been replaced recently or anything, I assume?

In my experience with my Bally pins, that used to be a problem with the coil stop or the flipper core.

If the core is shorter than normal because of years of use, or the coil stop is damaged and or shortened, the flipper core goes too far from the correct position and looses power.

Many people tends to think about EOS or voltages, but many many times on my Ballys the problem was the mechanical part.

In some cases you only need to replace the coil stop or the flipper core to fix the problem.

I was having a similar (not exact) issue with my Fathom. Ball would hit up flipper and it would go down and then back up. I searched for the answer and a few people said coil stops. I didn't believe them, but I tried anyway. It was the coils stops.

Flipper fluttering or chattering is usually caused by a bad holding coil. The flipper coil consists of a low and high restance coil in series. The EOS switch normally shorts out the high resistance coil until the flipper flips then opens putting the high resistance coil into the circuit. If the HR coil is bad the flipper will chatter. Try resoldering the coil wires or replacing the flipper coil.