I also had this issue (transport endpoint not connected) every few days.
In the end it turned out for me to be caused by bad memory. I was running Memtest for several days but got only rare errors (one issue every few hours) - so I wondered if that could cause the frequent shfs errors.
However, replacing the memory module totally solved this issue for me (no errors since 2 months now). So maybe you should also check your RAM.
[6.8.3] shfs error results in lost /mnt/user
in Stable Releases
Posted
I also had this issue (transport endpoint not connected) every few days.
In the end it turned out for me to be caused by bad memory. I was running Memtest for several days but got only rare errors (one issue every few hours) - so I wondered if that could cause the frequent shfs errors.
However, replacing the memory module totally solved this issue for me (no errors since 2 months now). So maybe you should also check your RAM.