I noticed that my TV had switched itself on after rebooting the Pi - only there was a “No input” message. I went in to check the CEC settings and noticed all to be as I had left them prior to the Krypton upgrade except “Switch TV to this source when starting” was enabled.
I turned this off and immediately lost remote control access. I checked my TV settings and CEC was still connected, but I could not control it. I rebooted the Pi and have control again and the setting is correct and rebooting the Pi no longer turns the TV on.
If that settings has changed it might confuse some people…