The swelling can be hard to notice, but definitely has a big affect on coupling with the implants
Make sure you check out
For tips on where to read the chip on your specific phone
Also make sure to play around with the xFD’s that came with the implant to learn placement
Also also, you can try the lf tune and hf tune commands on the PM3 to further refine the reading location
Also also also, just a quick warning, do be careful if you try to write to the LF side of the implant before being sure of coupling, it is possible to brick it.
Also^4, welcome to the community!
tl;dr: keep waiting and keep trying 