Stop redirect to network site when registering

I have a multisite and I’m trying to allow per site registrations, without going back to the network site. I’m having success using the ‘Join My Multisite’ plugin to achieve this.
However, when I enable TML the redirect to the network site on registrations comes back.

I’m guessing somewhere in the code there is a redirect to site_url() whereas I need home_url().

https://www.ads-software.com/plugins/theme-my-login/