How to reproduce:
-have a non-rotational device assigned to the array with the old partition scheme.
-wipe it manually or using the new erase function.
-start array and re-format with new alignment.
-reboot (or make any other array change) and will get a "wrong" device, since Unraid is still expecting the old size.
-you'll need to do a new config to re-accept the device but it will be unmountable, so any data copied since will be lost.
Emulated Disk8 appears to be mounting correctly, if contents look OK and there's no filesystem damaged (like a lot of lost+found stuff) rebuild on top.