new subsites redirect to main site after multisite migration

Hi,

I have moved my multisite to a new host.
The existing main and sub sites are working fine, but after I create a new subsite the subsite and its admin panel keep redirecting me to the main site.
I’ve contacted an admin at the hosting company but he says that everything is defined right on their side and that there’s something defined wrong on the WordPress side.

Can anyone say where the problem’s really?