Suddenly can only access certain settings pages via Incognito mode

Yesterday, I moved my VirtualBox home assistant setup from an old Mac Mini to a new mini Windows machine - and everything actually went pretty smoothly. Today I re-connected one of my services (I also moved Roon from the mini to the new PC, so had to re-add the integration to get it talking to the new core).

Anyway, at some point today, I started being unable to access some of my settings pages - like Automations and System. I just get an error like “Error while loading page automation.”

Other pages, like Add-ons and Devices, work just fine. I’ve tried restarting my VM, restarting the whole windows machine, manually clearing cache/cookies for homeassistant.local (via Chrome’s Privacy settings) to force re-login, and nothing has helped. However, if I open an Incognito window, I’m able to load the problem pages just fine (and was able to edit some automations).

What am I missing here - is there something obvious I should be doing that’ll fix the error?