HAOS at 100% CPU every day at 18:00 for 3 hours

You might be able to use this during the excess use events:

I have no idea how to interpret its output though. There’s a topic about it and Py-Spy where one of the devs will look at it for you if you ask. I’ll see if I can find it.

EDIT: here, https://community.home-assistant.io/t/how-to-install-py-spy-on-a-ha-os-instance-please-instruct/430822