keeps disconnecting from MacBook Pro

There are a few different things that could cause this. The fault could lie with the port on the computer, the cable, the drive enclosure, the drive itself, or your system software. If it's happening for consistently with multiple drives using different cables, I would be inclined to think the problem is on the computer side, either a hardware issue with the port or a software issue causing drive mounting issues. You could try rebooting the computer and logging into a separate test user account to see if the issue continues there—if it does, then the issue if probably hardware related. Good luck!