I have been using xFAT to enable my Mac and the PC to read the same files. The PC is only used for operating the Amateur Radio station, and I never accessed the Seagate drive with it. The 14 TiB external HD has a power supply problem and is in xFAT. It finally dawned on this eternal digital packrat: I no longer need the biggest HDs I can afford. It is getting replaced on the Mac Studio with a Samsung 4 TiB SSD; it will be formatted for APFS combined with the other Samsung 4 TiB SSB, and the Mac's internal 1 TiB will give me 9 TiB of storage, which will be plenty. Now, is there a Utility that I can use to convert NTFS to APFS? Searching the internet does not seem to give me much hope. If I have to, I will connect it to the PC and use this HD there.