Multisite dev site too many redirects

Hi there, I have a multisite at I have made a copy of it at that url /mls for development purposes. I followed the normal steps to manually move a WordPress install (copy all files, create a new database, import the existing database, change the site and home url’s in the database) Having done that, I could access the main site and it’s WP dashboard, but when I tried to access the network admin I got a “too many redirects” error. I followed the additional steps here (additional database table updates) and now I can’t access the site or the dashboard – too many redirects on both. Yes, I deleted browser cache and accessed through an incognito window. Then I tried deleting the domain mapping plugin as I thought that might be interfering – but still the same too many redirects error. Any ideas what I have done wrong? I can’t grant you support access – because I don’t have access myself….