I think it is mmap error 19 ENODEV which probably means that the -shm file is on file system which does not support mmaped files. Move it to a file system that supports this and it should be fixed…
See e.g. threads like this https://forum.openmediavault.org/index.php?thread/32959-mergerfs-sqlite3-plex-homessistant-disk-i-o-error/