@AdminAS Thanks for posting in our Q&A. From your description, I noticed that we have no compliance policies applied and if we choose to install it without checking "open in managed browser", we received error messages. If there is any misunderstanding, please feel free to let us know.
For our issue, it is better to check if there are any app protection policies assigned to related users or devices.
https://learn.microsoft.com/en-us/mem/intune/apps/app-protection-policy#benefits-of-using-app-protection-policies
Hope it can help
If the response is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.