No answers to this last time around and I am still having this issue at my site http://www.formelracing.se
I have multisites running as”folders” not subdomains, and if you log in to the mainsite formelracing.se and then go to for example formelracing.se/f1 you are no longer logged in.
It is a bit frustrating and some users don’t noticed “the bug” and just leave because they think something went wrong.