When the thick-thin rule style (or another that’s similarly asymmetrical) is applied to a compound path, the thick part is the outermost toward the outside of the shape, but not the innermost toward the holes or counters as one would expect. (I don’t recall seeing this in earlier versions, but I don’t use these rule styles very often.) To make the insides match (mirror) the outsides I have to stack copies of the object, each with its own simple rule.

Using v16.1 on MacOS v10.15.7.

P.S. Not sure what category this belongs in—sorry if it’s out of place.