I tried that and it didn't help.
But I did notice something. This is not problem for all channels, only for some. I can't find diference between them...
For example, for channels: FOX, FOX Crime, FOX Life subtitles are late when watching on ProgDVB but when watching over stream on VLC subtitles are ...

Try watching channel over stream (over Prog Media Server). Try it first with VLC player.
Open Prog Media Server Home (in 'Service' menu) and then click on button with label "Open" just up from button "Close".
Then click on channel that you want to test and download .m3u8 file and open it with VLC.

Hi,

I'm using ProgDVB Pro x64 7.17.02 version with DVB-C USB Stick ({BDA} ASTROMETA), OS is Windows 10 Pro x64.

I watch local cable TV and on some channels subtitles are available and when I select my language subtitle is shown over picture but it is not in sync with picture, it is often late but ...