Thanks for confirming. 
I found the culprit. It is actually the old HA VM in the Proxmox 6 notebook. Once i turned off that VM, all systems CPU usage went down to <10%.
Not sure what is wrong in that VM. I have not changed any settings so far except upgrading versions. Looks like now I have no choice but to force myself to move everything to the new 7080 micro. Hopefully everything will turn out fine. 
Update: Moving to the new system did not help after I configured network. As I have 3 networks that HA is connected to, the mDNS implementation of HA was causing issues even though I have not changed any settings previously both on my network and HA. I now have resolved the problem with a very simple fix that I mentioned in the other thread (Setup VLAN and HA tutorial - #66 by skull29). Hopefully it helps anyone encountering the same issue as me 