That’s what Zwift suggested to me; they should be dried off after a ride. I agree they should be sealed well enough that it doesn’t happen.
Try re-calibration but IMO they would need opening up to clean the circuit card contacts where the steering paddles input to the card; then re-calibration. But if still in warranty probably best just to get replacement.
Sorry to revive this topic, had the same issue with brakes being applied. Opened up the left controller, don’t really see a whole lot of corrosion or sweat ingress, and not a crazy sweater and have lots of airflow during rides. All I’d like to do is disable braking entirely at the hardware end, and I think if you can cut one of the connection wires that sends braking signal it may allow you to use the rest of the functionality of the play controller.
Not an electrical engineer obviously, anyone out there able to help identify which of the 6 signal wires I would cut? I’d be ok even if steering went away…
You can disable braking in Zwift settings 
Yeah, I am aware of that, but the controllers still vibrate as though the brake is being applied, so then you turn of haptic support, then you don’t get the tactile feedback of ride on etc. would love to just cut the wire so I can keep the rest functioning! Plus the replacement controllers are bound to fail at some point, rather than buying more or warranty claiming another set I’d love to just “solve” the issue.
@Kerstin_K_C2rower might know…
Not sure if it works but worth a try: Cover the connector side of the circuit board with adhesive tape to avoid the electric contact. You can try with a piece of paper first before reassembling.
Edit: Just gave it a try with my spare unit, it doesn’t work, sorry.
