Mistakes in Polish Map?

Hi,

hope this is not a newbie problem: I have attempted to filter geofabrik data on Poland with osmfilter such that I obtain a map of the administrative divisions at the municipality level ("gminy") which is admin_level=7. There should be around 2480 of them. However, in some areas (e.g. south of Warsaw) of the map, the divisions break down in much smaller units which are definitely not gminy anymore. The reason is that in these areas, there are ways which are incorrectly tagged as administrative boundaries. I have not been able to filter these ways in a satisfying way - either I do not get rid of the wrong boundaries, or I kill all boundaries. Are these mistakes in the map data which need correction? Any suggestions? Thanks in advance!