It's pretty simple: Instead of leve cancel when you log out / disconnect, the leve and timer would just keep running.

For example: When I trigger a leve, I have 30 minutes to complete it, wheather I'm logged in or not does not matter, the 30 minutes will run no matter what and I'll have the leve activated for all the 30 minutes (unless I abandon it myself)

So if let's say there's a party and someone disconnect, the rest of the members have the option to wait for them to log back in and continue (while wasting some leve time of course, but you can't prevent that if you WAIT)