Watch Series 4 stuck on water lock

I went swimming with my watch last Wednesday with the watch on water-lock before entering the water. It has remained stuck on water lock, and is not responding to me turning the crown (tried it in both directions and at speed). The crown is not vibrating/ticking as it normally does.

I've tried soaking the watch in warm water twice and letting it dry out overnight each time, with no luck. The screen is also non-responsive.