In reply to farmersquires:
Not a physio so not medical advice, etc. etc. Anyway:
I had issues with both of my wrists, I think due to spending too much time training and not enough time climbing during lockdown. Likely also having newly strong fingers and core but having not really worked any other part of my body, and then heading out and getting on hard things. I found that I started tweaking my wrists and these got increasingly bad, to the point where I really struggled with not just slopers but any holds that involved the wrist not being straight, as well as slappy/big moves. These sometimes caused a painful 'popping' kind of sensation in the wrist, which a physio later diagnosed as an inflamed bit of soft tissue moving past another; when this happened the wrist would be too painful to climb on further that day, and would take a week or two to stop being painful. I'd then climb again until I reinjured...
I went to see physios who diagnosed different things, but agreed that the key issue seemed to be wrist stability as well as constant reinjury. It got to the point where I was trying an extension of a boulder problem that I'd previously done, and a move that had been trivial in the past (a big throw to a sideways sloper) became the new crux because of how painful and tweaky hitting the hold was.
I found that strengthening the wrists while simultaneously preventing reinjury was they key; Hooper's Beta (https://www.hoopersbeta.com/library/wrist-stability-training-for-climbing-p...) has some really good exercises, and I came up with a couple on my own that seemed to be good. The most useful for me was getting in a plank position but a) on my knuckles and b) on a boulder pad. This really targets all of the little muscles in the wrist that stabilise it, and you can then make this a lot harder by doing things like plank pull-throughs () so that you're weighting wrists alternately. Months of that once/twice a week mixed in with core work and gradually upping the difficulty worked wonders, to the point where a year on that new crux move is no longer the crux.
Preventing reinjury was a case of getting a pair of knock-off Wrist Widgets (https://www.amazon.co.uk/Adjustable-Support-Triangular-Fibrocartilage-Injur...) and using them for any moves that felt like they might be, or actually were, tweaky. I initially just used tape and then strapping tape, which meant shaving my wrists and was generally pretty crap. The branded Wrist Widgets are stupidly expensive for what they are, but knock-off ones are great value. Pretty poor build quality in my experience but nothing that tape/glue couldn't fix.
Hope some of that is useful.