Plex is not displaying my movie posters

@ChuckPa What do you mean when you say you created a test file for “Crazy Rich Asians”? That movie downloads the poster for me too. On the picture I sent here Plex is not displaying my movie posters - #33 by tomyt3 the poster shows black because I manually tried to assign a new one.
@trumpy81 I once again don’t agree, my computer is fine, it’s a MacMini by the way. To confirm my computers are ok I now installed Plex Media Server on my other mac, a MacBook Pro and created a library with the same directory with the same movies. Same thing with posters happens on my 2nd computer!!! so it is NOT an issue with my computer/s. I tried using safari chrome and firefox.
Please beware what you afirm, or use the word ‘maybe’, if I followed your advises I would have bought FileBot, and now I would be reformatting or buying another computer.
EDIT: I reinstalled Plex as I told you here-> Plex is not displaying my movie posters - #33 by tomyt3 and here-> Plex is not displaying my movie posters - #31 by tomyt3. I even started a new post to understand how to do it Fresh start, as I said on my previous messages.
Plex Media (753.3 KB)