I am having the same issue and really need a new source or something to solve this problem. Here is a related issue. And they are saying it is working as intended. I agree that it is working as they intended. But not working the way we want it too.
https://obsproject.com/mantis/view.php?id=734
I want this to actually hide the source when the playback of a media source ends. Add options in the settings for "HIDING" the source and a setting for making the source "transparent". Leave "transparent" as the default selection and that would mimic current behavior but the "hiding" selection would actually hide the source. This would fix the problem for everyone. And this should be very simple to implement.
Also, I agree the bug is working as intended. However, it is not working the way some users would expect. So, it would be great if you could implement something to help out the users, instead of just closing the bug and going silent.
Other than that, thank you for your hard work and a great product. I really enjoy OBS.
Please give us some information on this issue.