Properly adjusting the EOS is a touchy operation. There are a few protocols to be followed.
Test the switch adjustment by pushing in on the plunger and not by turning the flipper.
The EOS should open at about 75-80% of the stroke.
Where there is an upper flipper the lower flipper will have a second EOS switch that activates the upper flipper. The second EOS should be adjusted break-make with the primary EOS.