Wrist pain on tops and while shifting

I have picked up a bit of wrist pain on my left wrist and I am hoping someone has some strength / stretching suggestions or a search term to look up.

I notice it either when going from the little ring to the big ring on drop bars, or when im riding the tops. It feels like the thumb is somehow involved, especially when shifting. It can be a pretty sharp pain especially when on the tops and drinking with my other hand.

I first noticed it last summer when I was riding a lot of washboard on the tops of my cross bike.

All my searching seems to be end up suggesting fit issues on the hoods which I don’t think is my issue. I have had a professional fit.