I created a new website in the panel. It works perfectly.
But I tried temporary to remove its public_html folder in terminal and now it has different owner:
rm public_html/ -r
rm: cannot remove ‘public_html/’: Permission denied
Access: (0751/drwxr-x–x) Uid: ( 1002/ myuser) Gid: ( 33/www-data)
Uid/Gid is now myuser:www-data, not myuser:myuser. I think it’s a bug. Before that I could remove this folder easily without sudo.