I need to access a customer's sharepoint sites/lists with my own O365 partner account (which is Global admin at the customer O365 tenant).
I've tried to add my account as a guest to the customer AzureAD (EndtraID) and then share a sharepoint list to the account, which I can, but I don't get access, it seems the account somehow conflict with the global-admin-link. If I use another account/email it works.
How can I archive this, I must get access through my O365 partner account (email)?
In the old days I think you cold add a Support Partner / Foreign Principal as owner, but it doesn't seems to be possible anymore, at least not in GUI, perhaps Powreshell?