会議中「ネットワーク帯域幅が低くなっています」

Hi ​@喜楽鉱業,

I apologize for the late revert. 

You can confirm network bandwidth issues in Zoom meetings by accessing meeting statistics, which show the current bandwidth used by Zoom. Additionally, you can use the Zoom Network Connectivity Tool to test meeting connectivity and gather network data. Running a speed test (such as Speedtest.net) can also help you check your available bandwidth. Zoom generally recommends at least 1.2 Mbps upload/download for HD video.

You may check out the links below to learn more.

Using the Zoom Network Connectivity Tool and Accessing meeting and phone statistics