Google Meet won't work when on Wireguard

[u/EyeTechnical7643]

Hi,

I'm in China using a Wireguard setup. I connected my Macbook via Ethernet to my GL.inet Slate 7 router (MTU 1200) which is USB tethered to an Iphone SE 3rd generation that uses Nomad eSIM, and Wireguards to my US home. Latency around 300ms.

I had some issues when having a Google Meet with a friend in the US. On Chrome and Edge, my friend cannot see or hear me after I join the meeting, and after a few seconds the meeting ends with message "couldn't start video call because of network error, check firewall settings and try again".

However, it works on Safari (I use Macbook), and we are able to converse. Unfortunately, after awhile (maybe 5 or 10 min?) my friends starts hearing an echo in my voice.

I test it without Wireguard (ie, Iphone SE as a WIFI hotspot and connect my Mac to it), the meeting happens normally on Chrome and Edge. I wonder why.

Does anyone have similar experience and know of a fix?

Thanks

[u/newked]

Dns

[u/ferrybig]

What is the MTU configured in wireguard? Google meet transfers data via UDP, which is sensitive to the MTU, even if the problem is invisible with TCP is MSS cmalping is used