Upper flipper stuck after cleaning optos

I cleaned the optos after noticing that my upper right Williams Flintstones flipper was becoming weak. After cleaning with a paper tissue (perhaps my mistake, didn’t have a cotton swiper handy) it was as strong as ever. However, after a while it stopped working, started with an error for the upper flipper switch being closed. Repeated cleaning didn’t help, and switching the left and right opto boards had an odd effect: suddenly the upper right flipper was working, but now the lower right and lower left stopped working.

I ordered two opto boards as a replacement, is this likely to be the issue given this problem description?