On SystemD systems devices listed in /etc/fstab which are not present at boot time but appear later are mounted automatically. Other systems don't do that (at least not all of them).
So you need something that triggers a mount /test call when the device has become available. This could be done with a udev rule (RUN=).
I guess you can boot into the recovery console? Try running e2fsck (man page) on it, e.g.:
e2fsck -f -v -C 0 -t /dev/sda2
If it doesn't help, please check your GRUB command line.
Edit: the issue was actually caused by dubious default mount options:
I've recommended to reduce them down to
which has ...