I ended up going another route. Thanks.
Not sure how the connection number would be different when set to multisite vs single site.
Also, the registry change is a Windows specific change. The OP and I are both on Mac.
Thanks for the input though!
I’m having the same issue, also on a MAMP environment in Chrome. I can log in to single, but not multisite. Cleared cache, restarted, et al to the above. Can log in with Safari no problem, just don’t like having to run two browsers to work on one site.