man that’s bizarre. Sorry for not having a definitive answer, but that’s weird.
Something you could try–disable one of the tuners in Device Manager, then go back to MCE, reconfigure the TV Signal, then test. If it happens again, try with the other tuner. Ideally you’d be able to physically remove one of the tuners from the system to do this test, but if not disabling in DM should be good start.
But man this is funky. I doubt copy protection has anything to do with this.
