iPhone Connects and Disconnects From Macbook

workoutfanatic wrote:

Problem: When I plug my iPhone into my MacBook Pro, it repetitively connects and disconnects. A modal pops up asking to either Trust or Don't Trust the plugged in phone but before I can press "Trust" and then enter my phones passcode, the modal disappears.

After searching for answers, but coming up short, I remembered a command you can type into your Terminal app that temporarily fixes this issue.

Solution1. :

Open Terminal on your computer by a) pressing "cmd + space" and searching "terminal" or, b) go to Applications > Utilities > Terminal

2. Type the following command and press enter (without quotes): "sudo killall -STOP -c usbd"

You do not say what exact Mac is this or what macOS you are currently running.

sounds more like a faulty cable or a faulty port...

for software issue—A SafeBoot Use safe mode on your Mac - Apple Support will sort many anomalies

Ref: If your computer doesn't recognize your iPhone or iPad