Oh and I forgot to mention: the same year (2022) the C6 got rebuilt in the RV, the vac hose somehow pulled totally off the vacuum modular. I blamed the vacuum pump and replaced it, but the problem didn't go away and I feared the transmission was already failing. I finally decided to check the modular and yep the hose was just hanging there disconnected.
It was going to 3 still, but it was late to 2 and 3. I have a thread about it somewhere from the time, as I recall.
In addition it was downshifting abnormally when slowing down for a stop. Normally it stays in gear when you're coasting at 15mph from say 40, but it would downshift instead. So that means extra wear from unnecessary downshifting.