I’m on the sidelines and still believe things being up to either userland util (busybox mount), but much more likely kernel file system support (for custom mount options too) being responsible. Sure I can be wrong, I never debugged this on an affected device to see where this goes.
It’s interesting that you say the starlte behaved differently after the reset and it must be up to “state” (filesystem, version?) if it’s mountable. I can’t contribute to this more without taking the time to go debugging.
“Is the devices USERDATA partition mountable in a recovery? (in case of FBE - filebased-encryption - it’s not required for this table if it’s decrypted and filenames are shown)”
device | /e/recovery (version) | twrp (version) |
---|---|---|
FP3 | yes on v2.4 | yes on 3.7.0 |
starlte | ? | ? |
star2lte | ? | ? |