Unable to Sign in or Join a Meeting. (Error Code 5003)

[NW22]

I got several users who cannot join to a meeting or login to their Zoom client. I got an error code for unable to join meeting (Error 5003). The login attempt, there is no error code but just a message "It looks like we are unable to connect. Please check your network connection and try again". It only happened to 3 users out of 20. 

2 users with login issues are on windows 11 and the 1 user who cannot join a meeting is on windows 10. 

They have no proxy enabled on their PC and there is no firewall block rule for Zoom. I have also changed the DNS address to 1.1.1.1 or 8.8.8.8 but no luck. 

All the users are on Zoom 5.16.10. Is anyone able to provide me with some insight? 

[bj56]

Hello, I am having problems signing into Zoom on my Samsung Android Tablet.

Message is "unable to connect"  Error message 5003