Hi, I tried posting the same solution in three places asking the same question, but not one went through as I'm told it's being caught by the spam filters.
This is what I tried writing, was related to WP updates not working:
I had this issue, turns out the root 'wordpress' folder was owned by another user which i used to upload and overwrite the default files.
This solved it (logged into SSH):
chown -R www-data:www-data /var/www/wordpress
a bit late but hope it helps you or someone else reading this!