So the live TV and recording problems have continued to plague me this week so I just did some more digging. Since I updated the SiliconDust drivers, the SiliconDust view app has worked flawlessly every time I've checked it, so I've been fairly confident that the SiliconDust side of things is good.
I noticed when I rebooted the PC last night (for some more Windows 10 updates - do those ever have an off season???) that I got a bit of an odd message for JRiver during startup and the JRiver tray service wasn't running (sorry, I didn't write the exact message down). So I shutdown JRiver and checked the Startup tab in Task Manager. Oddly enough, it was still configured to start JRiver MC22. So I started up MC22 and checked the settings and it claimed it wasn't supposed to start anything. After I flipped the settings back and forth and hit OK, the Startup entry for MC22 was gone in the Task Manager. That, of course, left me with no JRiver running at boot. So I started up MC23 manually, went into settings, set it up to run the service app and main app, and then confirmed the correct entry is in the Task Manager.
Next, I started up LiveTV in MC23 and it is playing fine now. It will take a few more days of testing, but it looks like this odd startup state might be what the problem was. My fingers are crossed that this solves the problem.
So Live TV and Records working properly didn't last long as the problem returned the next time I took a look at Live TV (on Friday). As before, TV still plays fine through SiliconDust viewer app on the same PC.
It was a busy weekend, so I didn't have much time to look into things, but after I found that TV was messed up again, I did / found the following:
1) I checked add/remove programs and had MC21, MC22, and MC23 installed.
2) I uninstalled version MC21, leaving me with just MC22 and MC23.
3) I installed MC23v30 from the downloaded installer, and selected the advanced option to select file associations and so on.
After doing the above, Live TV still has the same problem and, of course, recorded TV does too. To be clear, as stated earlier in this thread this is NOT limited to a playback issue as the problem recordings have the same issue if I open them in VLC, so something is getting messed up while writing the recordings to disc.
I really want to avoid the painful exercise of rebuilding the PC from a fresh Windows 10 install, but I'm starting to wonder if that's the only solution. If I have to do that, it would probably make sense to take it as an opportunity to update to newer hardware and replace the MB, CPU, RAM, and video card. I'm definitely open to less painful options though as I don't know when I'll be able to find the time to do that in the near future...