Adobe Express iOS app requiring a passcode

Hi

I am working in a school which has iPads. They are shared iPads and don't have passcodes.

When they try and log into the iOS app they get the following message - Your adminstrator requires you to set a passcode on this device to access this account. Please set a passcode and try again.

Background - we have synced their accounts in the admin console with their Google domain. Their Google accounts however have been synced with Microsoft.

So when they click to sign in with Google they type in their email address in the Google Sign-in window, then they they have to type it in again on the Microsoft sign-in page, then they can type in their password and they are into their Adobe accounts. Works fine through a browser on a laptop. 

Interestingly when I am using my personal iPad with a passcode I can sign in using the school account.

Another school who have synced their accounts in the admin console with Microsoft, don't have passcodes on their iPads and the pupils and staff don't have any problems. 

Is there a permission setting with Microsoft or Google that needs to be looked at or on the iPads? Woudl welcome any thoughts as it is baffling us?

Thanks inadvance for help.

Alissa