I don't think I have a custom effect that combines those two effects. However, I'm puzzled as to what custom list you are referring to "in the top left of FGU". Can you please clarify where I can look for this custom list?
FWIW, I did a test in a new campaign with the same extensions loaded and the effect works as expected--only Prone is applied. So, it must be something in this campaign that is causing this issue. I have been using Fantasy Grounds since 2017, but I must be having a brain fart because I can't figure this one out. :confused:

