I noticed my email address: lexshan@walkintour.com is associated with multiple ZC accounts. one is: lexshan1, the other is lexshan5

Here is what happened: i created an ZC app on lexshan1, then i added another user ( bayarea.bo@walkintour.com) as Administrator while keeping my account as Admin. Then when byareay.bo logs into the app, lexshan1 lost access right away, although Settings->Users & Permissions still show lexshan1 as admin. 

When I login normally with the email and password, I get into lexshan1.  When bayarea.bo user tries to share an ZC app to lexshan@walkintour.com again (since it lost access), ZC automatically treats it as lexshan5. I tried again just now and it treats it as lexshan8. The number behind it keeps increasing!!!

What's going on???!! Where can I start to diagnose this??

Many thanks!