Let’s try a few different methods:
First, unplug the cable and check for dirt or damage.
If every looks good, then try plugging it into another port on your Mac.
If that doesn’t work, then try the following methods on your Mac.
First, click the menu (upper-left corner of the screen), then click Restart…
After your Mac restarts, plug your iPhone into your Mac and see if that solves the issue.
If not, from the menu bar at the top of the screen, click Finder ▷ Settings…
Under the Finder Settings dialogue box, click Sidebar, then under Locations, make sure CDs, DVDs, and iOS Devices has a checkmark. ✅
Press Command ➕ W to close the dialogue box.
If that doesn’t help, then click the menu (upper-left corner of the screen), then click Force Quit…
From the dialogue box, click Finder ▷ Relaunch.
If that doesn’t help, then click the menu (upper-left corner of the screen), then while holding down the option key, click System Information.
Under Hardware, click USB and check if your iPhone shows up.
If it doesn’t appear, then it could require service, however; let’s see if this issue happens in Safe Mode:
Unplug everything except the power cord from your Mac, then:
- Shut down your Mac.
- Press and hold the power button on your Mac. As you continue to hold the power button, your Mac turns on and loads startup options. When you see Options, release the power button.
- Select your startup disk. It's named Macintosh HD, unless you changed its name.
- Press and hold the Shift key, then click the “Continue in Safe Mode” button below your startup disk.
- Log in to your Mac. You might be asked to log in again.
If the issue doesn't continue in safe mode:
Leave safe mode by restarting your Mac normally, then try to reproduce the issue.
If the issue doesn't return, it might have been resolved by the other things that safe mode did at startup, such as checking your disk and clearing caches.
