I have this same issue- buttons already placed on top of fences can remain until they are broken- then they can no longer be placed. It has been since the 1.20 update.
I am having this exact same issue. Plz fix Mojang! I much prefer to play MC with my pencil. I have better control, and its more comfortable than with my fingers.
I have this same issue- buttons already placed on top of fences can remain until they are broken- then they can no longer be placed. It has been since the 1.20 update.