Mac Garmin Express not recognize Edge 540

My Garmin Edge 540 (software v. 28.18) is not being recognized by Garmin Express (v. 7.26.0.0) my macbook running Sequoia 15.6. I am using the USB cable that came with my 540. I have tried manually putting the device into MTP mode, no luck.

This comes after an automatic update in May removed the map of Europe from my Garmin and it has been essentially useless ever since. Desperate for assistance. 

Thank you!