Disconnected. Connecting in xx seconds

[Avram Grossman]

There were several posts about this. Rebooting was recommended. However, it did resolve the issue for me.
I looked at Windows Services and noticed that 3CX PhoneSystem Management Console service was set to Automatic, but not running.
It took a few tries to "start" the service, and once started, I was able to log in to the console. FYI.

 

[NicholasP_3CX]

The first thing to do, especially on a windows machine, is to check the hardware specs of the machine.

https://www.3cx.com/docs/recommended-hardware-specifications-for-3cx/