Maintenance plan don't stop & don't backup all databases
If the job is still running, check what command it's currently executing with Adam Machanic's excellent free stored procedure, sp_WhoIsActive. After installing it (typically in the master database), you can run sp_WhoIsActive to list the running queries and see what command they're executing right now.

There's even a Percent Complete column that gets populated for backups and restores.

You might have a particularly large database (or log file) that's just in the midst of getting backed up.

For further followups &amp; clarification, try taking a picture or copy/pasting the sp_WhoIsActive results in, showing what the maintenance plan's currently doing.