firefox uploads

This is firefox-154.0p0 on a current/amd64. I am having trouble selecting files as uploads or as attachments to emails etc. This is what happens: I press whatever upload button a given page has ("browse files", "attach file", ...) and the file selection window appears. It offers Recent (empty) in the left bar, and "Other Locations". Clicking on Other Locations makes "Computer" (i.e. the / path) appear the right frame. Clicking on that goes empty again, probably because / is not unveiled. WHat is the right thing to do here? How do I make that dialog window offer ~/Downloads and /tmp, which are unveiled (rwc)? Thank you Jan