Probably it was some incompatibility between Google Meet and Firefox ESR.

Enterprise IT usually have blacklists. Microsoft has teamviewer on the list :/

Said it is the company policy to not use certain competitor's products, and it was neither time not place to drill down further. How it's enforced, I have no idea.

Beyond that, if you work at a company that large, they actually have to pay quite a lot to for their employees to use it.