Element hiding rules (cosmetic filters) do not work with regex

[mikeskk]

For example (tested using latest Brave 1.66.113 on macOS and iPadOS):
/example\.com/ - blocks the website
example.com##.adClass - hides the appropriate element
however,
/example.com/##.adClass - does not work (does nothing). It does work in uBlock Origin

The behaviour was consistent across multiple websites. My apologies if this is expected behaviour but I couldn't find any mention of this in the issues open or closed.