I have been dealing with the exact same issue ever since I got myself the iPhone 14 Pro Max. This is clearly an issue isolated to the iPhone 14 Pro Max and Apple AirPods (regardless of generation and version). I don't have any other iPhone 14 models at hand, so I'm not sure if it's isolated to the iPhone 14 Pro Max only, or if the same thing will happen when using iPhone 14 Pro, iPhone 14 Plus and iPhone 14 as well.
I'm no iOS or Microsoft Teams developer so I don't have the tools to verify what is going on. But I highly doubt Microsoft and the Microsoft Teams app for iOS is to blame. It's strange that this issue seem to only occur when joining a call or meeting in Microsoft Teams, I have no issue when using Facetime, Zoom, Discord etc. But I don't think there is anything the Teams developers can do to make the Microsoft Teams app somehow behave differently when using microphones from Apple AirPods in Voice Isolation mode on an iPhone 14 Pro Max compared to using the same combination on an iPhone 13 Pro Max.
If I pick up my old iPhone 12 Pro Max or iPhone 13 Pro Max it works as intended. Doesn't matter if I'm running iOS 16.1.x, 16.2.x or 16.3 BETA. It always works when using the exact same Apple AirPods Max, Apple AirPods Pro 2 or Apple AirPods 3 with microphone mode "Voice Isolation" activated on a Microsoft Teams call or meeting when using one of my older phones. The issue is only present when using my iPhone 14 Pro Max, regardless of what version of iOS 16 I'm running. With older phones it works regardless of what version of iOS 16 I'm running.
The culprit is the iPhone 14 Pro Max, Apple AirPods and microphone mode "Voice Isolation".
[Edited by Moderator]