Call quality

I am having problems with the quality on group meetings, with more than 5 - 10 people. We mute everyone and reduce the video to low bandwidth, yet some people still have problems.

They can’t hear or be heard, or be seen.
They have difficutly joining the meeting (or completely fail to).

Does anyone have any suggestions, please?

Would it help to download the app? If so how do I run the meeting through the app?

Many thanks

I had a similar issue and realized the latency was causing a lot of it. When i shifted to a server which was in my region and my users region things became absolutely fantastic.