So here's my take on all this. I noticed you don't have any Quick Keys programmed in, nor do I know how advanced you are on self-programming. It appears to me, you're getting another site or conventional frequencies since the P25 and Data symbols are disappearing when those frequencies come up. This would lead me to believe, they're not part of the site you're attempting to monitor or another "out of range sites" control channel frequencies have been added.
In Sentinel, Edit the Favorite List, pick your Favorite List, under Options drop box piick a Quick Key number. After that, under the System name in the right pane, scroll to the right and assign it a Quick Key. While under the same screen, in the left pane highlight the system. This will display additional fields and you can assign Quick Key's to Departments and if you click on the Site tab in the right pane, you can also add a Quick Ket to a site and review the frequencies. From here, I'd pick one site your close to to, cross reference the Control Channel frequencies only from the database, and delete any voice channels you added. This is where I'd start, and continue to modify as you go along.
As others mentioned, under the Site Option tab (not Global Filter), try the different Filters. I've watched a couple of your videos and see frequencies popping up that don't appear to be part of the site. When it sits on the site, it sounds good during the brief video. You might have added some errant conventional frequencies and if they're not assigned quick Keys, this is the behavior that's exhibited in my experience.