A fix is a strong word for it. More of a bandage that gives optimal uptime. Also doesn't account for other random crashes. The auto-restart would have to coincide with every backup, once every 7 hours except between 21:30 and 00:30, which is a shorter period. I would say that a better solution would be to remove the auto-backup and maybe have it backup any time the server shuts down or restarts instead. It's less safe in terms of backups unless you have an auto-restart fairly often. Will keep the server running more though, I think.
Yeah, it seems that the server backup is causing a strange crash where everyone gets booted and then can't rejoin, while the server still appears to be online in the list. A restart fixes this, but without auto-restarts it's hard to do.