Hello Jasem, I have the same issue. I've updated stellarmate to the last version 1.7.5 and filters are gone in ekos. I have to remove filters in Opticals Train, close it and set filters again. After that filters appear. Kstars does not see filters after connect, select box is disabled. But INDI can see it in CCD Filter settings and I can change it.
I have RPi4, QHY600L+CFW3 connected via 4pin serial. KStars 3.6.3 version, QHY SDK version 22.11.9, in logs I see string "QHY CCD QHY600M-c765284 filter is online.". How to solve this problem?