Deleted user comes back if the user access to the site as a member of a group

[motoki]

Hi,

I have a SPO site called contoso.sharepoint.com/sites/sales,  
admin1@contoso.com is a member of "admin group" security group.
and "contoso owners" group is a member of contoso.sharepoint.com/sites/sales site groups.

First, I added admin1@contoso.com to "contoso owners" group. 

Next, added "admin group" to "contoso owners" group.

Running Get-SPOUser against contoso.sharepoint.com/sites/sales returns 

contoso users 

----------------
admin group

admin1@contoso.com

That is no problem. Then I removed "admin1@contso.com" from "contoso owners" group by Remove-SPOUser and Get-SPOUser returns 

contoso users 

---------------- 
admin group

It is good so far. However, if admin1@contoso.com access contoso.sharepoint.com/sites/sales site with a browser (admin1@contoso.com is a member of admin group), Get-SPOUser returns "contoso owners" group and admin1@contso.com again.

contoso users 

----------------
admin group

admin1@contoso.com

Any ideas? 

[#2]

@motoki 

I have got a response from MS support.

The person is explaining that it is not feasible to get a list of the current SPO users using Get-SPOUser, because Get-SPOUser returns deleted users as well as active users of the site.

Is that true?

Regards,

Motoki