I purchased and installed the PGC Extension for both my android and IOS devices. I noticed the android devices aren't displaying all the items in the PGC catalog that are being displayed on my IOS device. I assume the problem has to do with deep sky magnitude limit on IOS can be set to "unlimitied" whereas android can't. I can search and find the galaxies not being displayed in android but they only appear when selected and disappear when not selected.
As examples PGC 2813776 and 2813775 will display in IOS when the mag limit is set to "unlimited" but will never display in android even when the mag limit is set to a max of 25. I assume because both galaxies have "unknown" magnitudes they can't get past your magnitude filter.
I suspect I'm having the same problem with GAIA cats i purchased, given there is no magnitude sitting of unlimited for it either,
I'm running IOS 12 & 13 and Android 7-9 on various Samsung tablets.