Ha, spoke too soon and now I have a new suspicion. It just turned the TV off again. Here is what happened. Was watching a youtube video via roku. The remote was sitting on top of my phone on a side table. I move the remove, pick up my phone (Pixel 5a for reference), checked a thing on the phone and then lock the screen, set the phone down, and then set the remote on top for easy access. A second or two later the TV starts to shut off so I glance over and see the colored LEDs cycling as if the power button was pressed. No part of my hand was anywhere near the power button.
So my suspicion, and this purely conjecture, is that maybe the phone is interfering with the remote. Some RF inducing a small current in the remote maybe. I lack the tools, motivation, and a backup remote to test that theory so...yeah...don't know where to go with that.