I'm using ProgDVB 7.33.07 x64 on latest Win10 x64. Using it only as IPTV client with XtreamCodes Catchup API.
I have K-Lite installed and using madVR with LAV video codecs activated (that gives the best possible experience for me, most fluid video with least stress on PC)
The problem occurs only when using catchUp (timeshift) functionality.
While playing live channels this clock in the right bottom corner somehow works ok. Every 2-4 seconds refreshes and shows new time pretty accurately:

When using catchup functionality this clock refresh is somehow buggy and it refreshes every now and then but changes only by a second.
Sometimes after cca 40s it adds only one second. Then after 15s it adds another and so on. I have also witnessed it has lowered the value by one second going from 17:10:14 to 17:10:13. when actually it should have been set to around 17:15:xy. Playback works fine, video works fine.
To put a real problem on a table, the Skip functionality is based on that timer so when I watched a show for 30 minutes and tried to skip (+60s) ads, my timer was at around 45s after the show started and it basically moved me back to the beginning of the show. after using skip for quite number of times I get to the position where I wanted to be but I think this should be traceable and fixable.
If you need more info about my config etc. feel free to ask.