Whenever I try to open a pdf file (automatically opened in Acrobat), Firefox hangs a long time, before eventually opening it in Acrobat. When I open the download dialog, it always shows the file is almost downloaded, but the progress bar always hangs near the end. When I go to the download folder, I always see the pdf I'm trying to open with a filesize of 0kb. This behaviour is the same for large and small files. Eventually (after several minutes), it just opens as it should. I already tried reinstalling Acrobat. The behaviour is the same in regular Firefox (102.0 64-bit win7) and Firefox developer (103.0b4 64-bit win7). It is specifically with pdf files. Other downloaded documents seem to open as it should. Can someone help me to trace and solve the cause of this issue?