Unable to FaceTime over WiFi
iPhone 6s Plus
iPhone 6s Plus
There is not a lot of troubleshooting you can do with FaceTime. See this for steps from Apple, If you can't make a FaceTime call on your iPhone, iPad, or iPod touch - Apple Support Are you using a VPN?
That can indicate a degraded wi-fi connection on either side of the conversation. It can be yours, or the person you are calling. It will happen at times. Issues occur with bandwidth and other issues. It normally will correct itself in a moment.
At this point, I would recommend that you contact Apple Support. Especially since you say it works fine on cellular. It may be something with your ISP, but Apple may be able to diagnose that. Use the Contact Support link at the top of the page here to contact them.
Even I thought that initially. But prob persists. I have a high speed fibre connection.. problem occurs only on WiFi. As soon as I switch to 4G it works fine.
And you have checked the wi-fi of the person you are calling? Are you saying that it will never connect?
Yes. The other person is also on high speed fibre. It's happening with all FaceTime calls. My WiFi speed is 120mbps
I have tried these steps already. They did not resolved the issue. I'm not using VPN
Unable to FaceTime over WiFi