Hi Maid,
Unfortunately I can't help much, as I only use RO HQ on my workstation run as a MC Client, and I just use the default madVR settings, and the MC settings as I described above. I just don't need to use anything else to get good quality video. On my HTPC I am still using RO Standard as I only use an Intel iGPU, and it isn't strong enough for RO HQ.
If you want to get back to the default madVR settings there is a batch file in "C:\Users\[UserID]\AppData\Roaming\J River\Media Center 21\Plugins\madvr" called "restore default settings.bat" which will do that for you. You may want to take a note all your current settings first though.
But if you have one, or just a few, 24fps files that don't play well, delete them and find another source of the same thing. Or use a video editing tool to re-encode them so that they work. Of course, the bad file(s) may just have such a low bitrate that they will never play better.
Sorry, but that is about the best advice I can give.
However, if you really don't want to source new copies of the problem files, and do want them to work, you could try specifically listing all video modes that you want to use with your TV. For example, on a full HD TV they might be as per the attached image. I don't know if that list is conclusive, but it is valid, for a 1080p TV. You can now get to that madVR dialogue without having to play a video and right-click, via "Options>Video>General Video Settings>Open madVR setting (Advanced)...".