Sounds like a compatibility issue. I'd go with the 1TB for now that works. After the full blockchain is downloaded you can copy the nvme later.
Would a USB to NVME be detected and compatible with the 2TB installed into the USB? This could allow you to copy the data. If you could mirror the 1TB to 2TB after full download would the mirroring solve the compatibility issue? Good catch on startup error message.
Does the raspberry Pi onboard the Apollo 2 have an Eeprom? And is it possible the fix the incompatibility issue I'm having with my 2TB nvme by installing the latest official raspberry eeprom?
And if I do that are there any settings I'll mess up which will result in the apollo OS not working as it should? Thanks in advance

(Btw the 1tb older nvme is syncing the blockchain is at 80% at the moment)