If you look at the description of above mentioned methods in interface, you will see, that the array or the object should be skipped if the parser is inside the array's or object's context. Not at the beginning. These methods implemented correctly in the JsonStructureParser, but not in the JsonParserImpl. Here, one can't skip to the end of the array or object if one is already inside the context.
Found this during the test for this Yasson ticket 630. I'll create a PR with changes to correct this.