MacBookPro won't connect via Thunderbolt, but will by USB?

Hi, I’m hoping someone can help me fix an issue that appeared a couple days ago. I have a 4Tb G-drive that I use with 2 different MacBooks (an Air and an older MacBook Pro). When I connect the Thunderbolt cable to the MacBook Pro, the drive powers up/wakes up, but I cannot see it. It used to appear on my desktop. I’ve checked in Disk Utility and it doesn’t appear there either.

When I connect this G-drive to my MacBook Air with the same Thunderbolt cable, it appears like it should.

When I connect the G-drive with a USB cable to the MacBook Pro, I can see it and access my files.

I’ve restarted and replugged in many times and I still cannot see the drive when using the Thunderbolt cable.

Thank you in advance.

I should have added that the Thunderbolt port on the MacBook Pro works properly when I have a LAN cable connected, so I don’t think it’s the port.

How old is the Macbook Pro? When you have the drive attached to it check the System Report when you go to Apple Menu > About this Mac > System report and look at the Thunderbolt section, does it show the G-Drive attached?

It is possible the TB interface is not recognizing a data connection for the device but can still transmit instruction over a LAN cable. The performance would be the same whether it is attached via TB or USB however so if one works you can still get everything out the drive that you will need. You would need to work with Apple to diagnose if there was an issue with the TB port on your MacBook Pro.