User still having problems signing in, even after admin redeployment

I understand Google have made some changes recently and I have followed the instructions.

We have removed and re-deployed/accepted the terms in our admin centre.
All users in our domain (all OU’s) can run Sketchup.
This particular user was an existing sketchup user and it would always work for him.
Other users can use sketchup. Our design teacher still cannot.
Checked for pop-ups being enabled.
Checked it is all accepted in Google Admin.

We are a school in the UK. We solely manage our own Google Workspace / G-Suite and do not have district admins etc.

I am a super admin for our domain and all users.

Please advise what we can do next to get our users using Sketchup again.

@Steve_Ketchup are you able to assist?

I’ve begun getting the “g-suite/pop-ups” message and cannot get into SketchUp for Schools to look at shared drawings in students’ Google folders. I went and tried to make a new educator account to link to my Google account and I cannot launch SketchUp at all, nor view student work. I’m seeing something about whitelist…? is that the issue?