Impossible to upload images

Hello,
About two weeks back, I’ve decided to transfer my website photonomedecine.org built with wp.org to another host. I’ve moved it from GoDaddy to EvxOnline (a French company which I use to host other WP websites without an issue). The new host did the transfer themselves (FTP and database transfer).

Since the transfer was done, when I try to upload a new image (either to an article/page or directly in the media library) I get the following error message: “Unable to create directory uploads/2021/06. Is its parent directory writable by the server?”

I directly contacted my new host EvxOnline who checked my CHMOD rights and confirmed that everything is ok. Neither is it due to a maximum upload capacity that would have been reached or anything that sort.
After digging deeper, my host told me that this is the error message they could find in the logs: “Got error ‘PHP message: PHP Warning: file_exists(): open_basedir restriction in effect. File(/home/USERNAME/public_html/wp-content/uploads/2021/06) is not within the allowed path(s)”

They are not able to help me further and were suggesting that I should change the settings of my website so that it uses the folder in which WordPress is now being installed (/var/www/vhosts/photonomedecine.org/httpdocs/…) as the path has changed (it seems like the path is the one of the old host).
Any clue how to do that?

Thanks a bunch!