Andrew,

Most probably not related to OS or QCAD version.

When hatching an area with Hatch from Segments (HS) there might be false positive warnings on open loops.
It seems that this is related to the orientation of the indicated segments and the order of selection.
The real problematic position is not always the first that is reported.
Loop count is increased even if it is a single loop.

Included a basic test drawing to replicate these.
Further details to replicate the issue are in the file.

Regards,
CVH