MFA Office Phone calling should identify extensions by comma
Users are typically set in AD with a comma preceding their extension for their Office phones. This is so that users can click on someone's phone number using their cell phone to dial numbers automatically.
Having to change to " x" breaks this functionality that and in turn when calling from a shared company number, random users become associated with the caller ID.
In short Azure should be able to work with commas to be able to identify and dial Office phone extensions to prevent breaking other systems.