Sorry for the delay at the PPCC conference.
I was mentioning Teams / M365 because each have their own Admin. In each admin you can place policies, blocks and specific publishing rights (including admin approvals), so they are not simply a single entity but multiple.
I also brought it up because you said you were going to be building across Teams and M365 unless I misunderstood what you typed, which is possible, I am old lol.
So for instance when you share it across, that doesn't mean for sure that it will then work in Teams for people, meaning them being able to add it just because you tried to share it. Depending on what it does, what policies are there, it could be different for different people in each Channel type (m365/teams), so to be safe its good to make sure in both of those, as well as at the tenant level, there are no weird, unanticipated configurations.
So for instance this is m365 admin for copilot and while they are there you then have.
Teams admin for apps
And any level of Tenant (which is different and Environment settings as well, if they are Managed Environments)
So there are many places to look for reasons why 1 person works and one doesnt.
You have to be able to compare both people to see what's different across their accounts and as it relates to their... Tenant , Environment and App level permissions
