In my adjusting experience, the left and right arms on the Shiv TRP brakes don't move at the same rate as you squeeze the lever. Almost like one arm starts to move, then the other.

I adjusted mine so that both pads touch the rim at the same moment - even though it doesn't look totally balanced while squeezing the lever.

I had the same problem. Looked desperate first despite of several trials. Then I did the following:
- disassembled the brakes
- cleaned all parts thoroughly
- applied clear vaseline type of lubricant (do not use oil- it does not work properly ) - not too high in viscosity
- assembled all parts back paying special attention to placing the springs properly (make sure this goes absolutely right - this is critically important) and first turning the spring adjustment screws to outer position
- then adjusting the wire tension so that there is appr 1.5 mm space on each side between the brake pads and the rim - adjusting the barrel fine tension adjustment to almost loosest position
- then adjusting the spring adjustment screws on both side tighter- pressing the brake and monitoring that both sides return similarily and adjusting for any imbalance

Now the brake works perfectly! no issues - both sides returning to their right position after pressing the brake.

I think there is nothing wrong with the TRP brake itself. it just needs to be kept clean, properly greased and adjusted.

Good luck!