I have been having trouble too. I went to my settings and cleared my cookies and cache in chrome. Then when I posted my recent comment, when it wants you to select a size, I choose medium rather than actual and it worked. However as many people have said, I made my post without the photo. Once that went, I went in to make a comment on my own post and put the picture there. That worked!

So I'm on my PC but for many months I can not post on my android phone even if I use desktop settings. What can I do and or what's wrong? Google Pixel 3axl

There are MANY posts/complaints on the internet -- apparently an OS update in Nov introduced an issue with both Safari and Chrome.. they both released updates to address the issue. Since it is a new machine, make sure you have the most recent updates for the OS and your browser. It that looks good-- here's a fix that a few people said worked for them: "i was having the same issue (m1 mac) and think i found a fix. i went to system preferences > security & privacy > privacy > files and folders, clicked the lock, selected chrome (which already had Downloads Folder permissions), removed it (click the - button), and restarted chrome. then i was getting proper finder pop-ups for file uploads (and downloads were still working too)." If this works, it should address your issue saving files (which also uses an OS popup) Good luck!

Yes, it's still there and I posed a picture.