Impossible to log in a zoom because of the problem of ports

[yojiro]

I can not  log in an account and take part in a mtg. The error message says [Network error, please try again]. 

I tried to do some solutions written in this pages but I could not understand them: https://support.zoom.us/hc/en-us/articles/201362683-Zoom-のネットワーク-ファイア-ウォールまたはプロキシ-サーバーの設定

However, I could fix it even though I turned off firewall although I can jump to https://zoom.us.

I guess the reason is that port for connecting because I changed the setting of it in order to tackle another problem.

could you tell me what should I do?

env: macOS Big Sur 11.2,  zoom version: 5.8.3 (2240)