Featured Image not saving

Hi,

When I try to add a featured image to a post, it’s not working anymore. I can see that the image is loaded but if go to the post, the image is not displayed and if I go back to the post (or just refresh the page), the image is gone.

I tried to use Health Check & Troubleshooting to check if there was a conflict but everything is working properly.

Someone has an idea, please?
Thank you for your help!