I've also had the same problem with my rear brakes (Rize 17Ah version) and replaced with Shimano B01S organic brake pads. Initial impressions are good for the B01S, however their initial bite isn't as great as the Tektro pads they are replacing (so far). I have a small squeek coming from them but not the same flushing noise as before so they may just need some adjustment. I cleaned the rotors with isopropyl alcohol before installing the new pads.
I've attached photos of the Tektro pads, which appear to be potentially contaminated (black streaks)? The bike arrived with the rear brake and wheel fully assembled, so maybe it's an assembly issue at the factory.
I've attached photos of the Tektro pads, which appear to be potentially contaminated (black streaks)? The bike arrived with the rear brake and wheel fully assembled, so maybe it's an assembly issue at the factory.