Just got mine back from GD after the same thing happened to me.
I suspect mine broke as I sometimes slam it down against the clamp, as well as the cable being slightly too short, when running it at full height (running a large frame and prefer to run it rearwards, then along TT)
Anyway, emailed them when it broke, received a reply within 30 mins. It was 3 years old too, but they agreed to a warranty repair at $18 to cover shipping, incl full service, replacing all plastic internals, new cables etc.
It took 2 weeks total to be returned, and the work looks good. I’ll maybe stick pics up later if anyone is interested, but in essence they’ve glued the spring mechanism on, then backed that up with four screws into the post through the spring mechanism. It looks pretty bombproof!
It has however taught me a good lesson: never espouse the benefits of how reliable something is, as it will always bite you!