Favourite channels are hidden in Favourites list

I have a problem with viewing TV channel list that contains only channels that I have marked as Favourite.
After I imported a tv channel list from my local IP-tv provider, then all channels are showing ok in their list.
Then I marked channels that I like as Favourite. I saw all these from Favourites list.
After some time this list got empty!? I noticed that channels, that I marked as Favourites, still have ,,Favourite“ mark active in the ip-tv provider’s channel list. But they won’t show up in ,,Favourites“ list unless I untick ,,Favourite“ and then retick channel as ,,Favourite“.
I like many channels and manually reticking them is a lot of waste of time.

Can someone help me out? I have already tried to reinstall ProgDVB.