Or the internals of the lever sticking? - can isolate that option by disconnecting cable from the lever (or loosening it at the lever) and then using a pair of pliers to pull the cable to check the brake?
Maybe cable inner fouling on the inside of a cable stop?
Or the internals of the lever sticking? - can isolate that option by disconnecting cable from the lever (or loosening it at the lever) and then using a pair of pliers to pull the cable to check the brake?
Maybe cable inner fouling on the inside of a cable stop?