iPhone and photos app issues

I'm having issues connecting my iPhone 8 Plus to my MacBook Air. When plugged in, it opens the Photos app but then it's as if it immediately disconnects and reconnects, causing the app to flash/reopen instantaneously over and over nonstop. It makes any other computer app unusable and I'm forced to unplug the phone to get it to stop. I've already tried reopening the Photos app in Repair Library mode as well as Mac OS is current (big sur 11.2.1) and it did not resolve. How can I get this to stop so I can backup my phone to laptop?