Mercury Transmit working on every monitor except the one I need it to

Premiere Pro, latest version, Windows 10, also current on updates. The card is a GTX 1650.

Transmit works whenever it pleases. Yesterday it was working, the day before it wasn't. Today it's not working either. I need it on my third monitor, which is my TV set. The TV set displays the Windows GUI just fine, and I can even move the Premiere GUI or parts of it there with no problems.

In Premiere's preferences, if I select the other two monitors, when I toggle it, it displays in both monitors, badly, because I learned the Transmit doesn't like monitors that are set to anything but 100% DPI. It shifts the output vertically the first time I do Alt+Tab. That's why I set the TV display properties to 100% scale and it was working just fine. But then it doesn't. It's like a lottery. Maybe tomorrow will work.

Any suggestions?