Login User Field multisite problem

Hi i created https://buildnrank.com as a multisite. As soon as i create a new site within in, and then try to login the user login goes to the left and i cannot log in. If logged in (through the main website) it also happens when i log out (See picture)To make it quick here is the
login to the multisite: https//buildnrank.com/wp-admin. User: Removed by staff pw: Removed by staff

If you log in through this mainsite, everthing is fine. But if you try that though https//buildnrank.com/ofwebbooster/wp-admin , it goes wrong. What canI do, or what can you do to fix that for me?

I also have the same problem with webpowerbooster.ch

please adive, or better help me to fix it.
Kind Regards