Yes I noted that.

All would've worked if the microsd would've let me write anything on it. Later I discovered an ctioctl error in my microsd's btrfs filesystem which was the root of all my problems from the beginning. I guess it's just unstable in my microsd since I haven't heard anyone else complaining about their btrfs-formatted microsd. I had the problem since the start. I have a Transcend TS64GUSDU1.

Sad ending though as when I found the problem and decided to get rid of btrfs from my microsd I had a momentary lapse and typed mkfs.ext2 /dev/mmcblk0 on my Jolla phone (must be because in my Ubuntu the sdcard is always in /dev/mmcblk0, and I used it a lot formatting the microsd.)

Well, Care Centers exist, and luckily I live in Finland.