CalendarAgent eating up CPU on BigSur

[Fuga]

Anyone else seeing CalandarAgent running wild? At least it's not WAY up, like 100+% but it's reliably 30-80%. I can force quit it and it does calm dow, but creeps back up eventually. Luckily it doesn't affect performance (2.3 GHz i9/32 GB RAM) but pisses me off. I don''t have Big Sur on my internal SSD, rather it's in an external SSD. I did update the internal in hopes that difference might be the difference, but nah. So I returned to Catalina on the internal.

Anyone?

 

[Fuga]

For anyone paying attention ... I could never fix it. But! I did a clean install and then via MigrationAssistant brought over all user data and apps. All is good! Fuga is happy.

(On the external drive BigSur install I had thoroughly tested all my apps and services I needed and only with v11.1 did all work just fine, excepting the friggin' CalendarAgent.)