I'm currently on travel and can not have a look into the settings menu itself, so recovered only from my mind: "Make KODI the active source when starting" should be enabled. But your log output already looks so.
Also I can see that the CEC line is shortly disrupted during AVR off and on procedure. But this is expected, as I know that from my old Denon as well.
Like assumed, the TV sends no stream path information until you switch between the ports manually. At least it looks so. Without timestamps enabled ('cec-ctl -w -M' should enable that and verbose as well) within the log and additional knowing the timestamps for your step list, I 'm not able to be 100 percent sure which messages matches to your 7 steps.
The behaviour of libCEC shortly after sending the stream path information resembles a routine that typically runs after Kodi starts up from a powered-off state. The command sequence triggered in this process is known as "One Touch Play." It is quite possible that the aforementioned fix for libCEC 7.1.1 is the cause of this new behaviour. From the perspective of CEC specifications, the new behaviour is not incorrect (or "more correct"), but your specific use case is not covered (or has never been covered) by libCEC. The difference is simply that this situation is now noticeable.