For a while, some application/system part leaves files with names such as 2F__qbBz.html.part on the desktop. At least when I discover and inspect these, they all are empty (size 0).

I am using Kubuntu 22.04, and this behavior certainly did not occur in the past. However, so far I have not been able to find the source of the problem.

What application may generate these files? It looks like some intermediate result from an HTML file download, but what application could place such intermediate files on the desktop?