You can fix this by adding the two problematic paths to a config file.
Press and hold each entry to open the context menu and make a note of the full path.
Navigate to ~/.config/harbour-file-browser/harbour-file-browser/, then select the file ignored-mounts.json and press the pencil icon to edit the file.
Add the two problematic paths to the fullPaths list in this file.
Restart File Browser. The two entries should not be visible anymore.
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(This post should be linked in the how-to section; I noticed however that I cannot edit the top post anymore…)