Autofill rules incorrectly applied with multiple sites in one entry

See the screenshot for the autofill settings. I left the default for paprikaapp.com but for the second entry I changed it to be an exact domain match (since I have lots of custom stuff on aeum.net subdomains where I do not need/want this password).
However, when I login e.g. to my router (router.aeum.net) I also get this particular login offered. When I set both autofill rules to exact domain match, it disappears.
This is clearly a bug. Unless "related websites" uses some REALLY weird logic (is this documented somewhere? Is there a debug mode to see if the extension considers a site "related"?)
FYI this happens both with and without the desktop app integration.
1Password Version: Not Provided
Extension Version: 2.11.10
OS Version: Win 10
Browser: Firefox
