Firefox 98 changed from saving downloads in the Windows Temp folder for "Open with [relevant application]" or "Use [relevant application]" to saving them in your default downloads folder. (It's not possible to pass a file to an application without saving it somewhere.) This change addressed problems with data loss for users who could not re-download files they forgot to save after they were removed from the Temp folder. However, now users who preferred those files to be "out of sight, out of mind" are faced with the task of cleaning them up manually. Firefox 102+ has an option to switch back to starting downloads in the Windows Temp folder and I suggest testing whether this makes any difference. (But it does mean that if you "Open" a file then you need to remember to save it in a normal folder that doesn't get cleaned out.) (1) In a new tab, type or paste '''about:config''' in the address bar and press Enter/Return. Click the button accepting the risk. ''More info on about:config:'' [[Configuration Editor for Firefox]]. ''The moderators would like us to remind you that changes made through this back door aren't fully supported and aren't guaranteed to continue working in the future.'' (2) In the search box in the page, type or paste '''browser.download.start_downloads_in_tmp_dir''' and pause while the list is filtered (3) Double-click the preference to switch the value from false to true (I don't recall whether that takes effect on your next download or after you next close and restart Firefox.)