[SOLVED] Umounts happen automatically

[TheChosenOne]

I have two devices mounted. An external SSD and a USB stick.
After a few hours, they both get umounted. I don't know why. I've checked journalctl, but there is nothing unusual logged. I've tried to mount the USB stick without the SSD plugged in, and the same happens, so it's not a power issue.
I've updated Arch without avail. I suspect this is a hardware problem
I'm running ARMv7 on a Pi 3B.

Anyone else having the same issue?

[TheChosenOne]

So I bought a new Pi (Pi 4). Deployed everything. Same problem!

Turns out if you mount in an ecryptfs encrypted folder, things get unmounted after a while. The solution is to mount outside the ecryptfs folder (eg in /mnt) and create a soft link. In sshfs, you can use -o follow_symlinks to make sure it still works when you mount the folder on your local pc.

After the latest upgrades, everything is fine again, even on the old pi. So, it was not a hardware problem. Case closed.