Can not connect to zoom on macbook pro.

Hi,

I am currently need to setup zoom for my daughter. But I keep have problems connecting to zoom on macbook pro.

Here is what I have tried.

1. Wifi connection is good, google, youtube or streaming video are good.

2. Mac OS is up to date. Currently on 10.15.7 Catalina.

3. Permission has been given to zoom on mic, camera etc.

4.No fire wall enabled.

5. No antivirus software.

6. Have already reinstalled the software.

Type in the name and password and click the sign in, after a few secs attempt, it come back with error message"You are unable to connect to Zoom, Please check your network connection and try again."

And the funny thing is that if I click the "sign up", it will bring me to the webpage"https://.us04web.zoom.us/signup".

with the "." before the actual address. And if I delete the dot, I can straight away visit the website. 

Does anyone know about this?