You have a network for employee’s personal phones and devices, correct? That still leads to the Internet, correct?

I mean, the entire point of such a network is to keep outside devices off of internal networks that have sensitive data. And because the insides of large buildings can be absolutely sucky at receiving LTE/5G data connections, employees can and will do anything needed to ensure they still have connectivity on personal devices. So just connect the router/bridge to that network, and Teams will be appropriately sanitized and think you are still at home.