This sounds like a power supply issue. In my experience you get ticking from 2.5" external drives when the power supply isn't quite up to it. I always had to use a powered USB hub to feed 4TB drives from my Pi 4B (I now used a Celeron box with my 4TB drive), as the stock Pi supply wasn't quite able to provide enough power.
I was able to find my Chromebook charger which is 1.4A and that seems to work. I will get a higher rated power brick.
Thanks for your help.