Big Sur Home.app suddenly requires iCloud Keychain

Question

I'm using the same set of connected devices in Home.app on two Macs (both on Big Sur), an iPhone and an iPad. All of a sudden, the Home app on one of the Macs prompts me to enable iCloud Keychain in order to use it (see the screenshot below). I never used iCloud Keychain, and I frankly rather wouldn't have my Keychain in the Cloud. I do use iCloud for Home.app.

The other Mac and the iDevices still work fine without iCloud Keychain, though. Is there a way to get Home.app to work as before without iCloud Keychain?