Thanks for raising this issue.

In josm I fixed this issue class so long until the validation button did not raise any more related errors (only false positive warnings).

As a matter of fact, I cannot reproduce the warnings you have noted by downloading data of said bbox.
The validation panel does only show a self-intersecting lines warning.
It shows a "ways at the same place" warning, but that is to be expected for indoor, they have a different level.

It is pretty difficult to notice this class of issue and where it is wrong.
Do you use a different overlay/plugin/.. in josm?