Why aren't critical differences between version # 1 and 1A addressed?

PS5 controllers come in different versions. The FCC number can end in "1" or "1A". Apparently R1 / L1 buttons differ since the ones I ordered will not fit my controller. Few companies selling these replacement buttons seem to understand there is a difference, let alone the specifics. So where can I procure an R1 for my "1A" model?