issue switching between org-s

I have a problem switching between two org-s.

I have an org A which im administrator of and i m guest of org B. If i log in to org B i can switch to from org B to org A in the upper right corner no problem, then the option disappears  when i want to switch from org a back to org b. I need to log out and log in again to see org b. i also don't have option to switch to org b if i log in to org a first. i have personal free account and ORG b is using O365 i think. Coworker has no problem switching from org A to org B.

Also why was new account generated (free school and business account) when joining ORG B?