@52d87c48 Do you have suspend enabled? I had a similar issue with (in my case) "everything is read only" when enabling suspend on postmarketOS booted from SD card. SInce the microSD card reader ADFAIK is connected over USB internally on the #Librem5 and USB being a bit notorious for being difficult with suspend resume, I suspect this is the issue.

(I have 0 experience with using the SD card in PureOS for /home; for I mounted a music folder for a while (read-only would have been okay)).