OK, now the output of blkid on both cases gives me the right format, and changed the fstab accordingly.
I had done the mkfs.ext4 commands, I tried again on sd4, and it told me:
/dev/sda4 contains a ext4 file system
last mounted on Mon Oct 26 20:21:35 2020
Proceed anyway? (y,N) y
/dev/sda4...