The computer or device that’s hosting the group call needs to have enough processing power and network bandwidth for the call. Group calls with a large number of people can sometimes put too much strain on the host device and cause call quality problems. Make sure the host has a strong network and powerful processor, or reduce the number of people on the call.
If the host device isn't the problem, the most likely reason for poor vide quality is a bad internet connection. Check out our guide to solving connection issues for help with this.
If the internet connection is good and you're still having video problems, check our troubleshooting guide for more help.