That problem can happen if one of the game coil diodes comes loose, or it just fails. During multiball play, it happens possibly due to the flippers constant use during multiball. The cheap solution is to check if any are loose, and then to replace every flipper coil diode. 1N4004 diodes are cheap and easy to replace, and you have to desolder 1 side to even check them with a DMM, so worth the few minutes to cut the old ones off and replace them with new diodes.

May not fix the issue. Could be a 5 volt drain, that would put focus on the power driver PCB.