iPhone constantly disconnecting while working in Xcode

I think this is not the problem with the device/Mac port/USB cable.

This seems to be an issue with usbd in Mac OS. The following can solve the issues:

Open Activity Monitor -> View -> All Processes -> Search for usbd -> Double click -> Quit -> Force Quit

Using terminal:

sudo killall -STOP -c usbd will pause the issue related process

If you want to resume the process for any reason use the following command

sudo killall -CONT usbd

This solution is working in MacOS Catalina as well.

In the end removing expired certificates (current ones were already installed) solved the problem.