Agree.Try lowering the value of C5.
How much did you lower it?I lowered the value of C5 but the same problem.
To 1uFHow much did you lower it?
A simple tactile switchWith no clue at all as to the functionality of that unknown four terminal device you get no analysis.
OK, Max, and thanks. But it does not look like any switch symbol I have seen before.A simple tactile switch