The link is https://teams.live.com/_#/unsupportedBrowser https://teams.live.com/_#/unsupportedBrowser I imagine this is what Teams forwards you to when it sees

The link is https://teams.live.com/_#/unsupportedBrowser https://teams.live.com/_#/unsupportedBrowser I imagine this is what Teams forwards you to when it sees FF Nightly as your browser.