progdvb.com

I think this is reason. ProgDVB rendering in some small resolution and not detect 4K.
OK. This is not important. If you like use this mode then can use it.

Here are some pictures that shows why I choose to override thye systems High DPI .
This is how it looks if I don't override system high DPI
compared to my settings where I override system high DPI

And when program started it looks like this

High DPI enabled

and when I override system high DPI

Yes. This is reason why too small space for next epg field. Interface scaled.

You can change ProgDVB fonts in Options->Interface.