Hello, this happened sometimes already with Antergos as now with EOS. Normally one reboot would fix the situation. Now it seems to be the result of every boot. /b resides on a data disk holding music, video and documents. It has manually partitioned and configured to be mounted on every boot. Now EFI seems having hijacked the disk?!
Can it be that some yesterday’s updates have caused this somehow? This happened today that I cannot work around this anymore.