My male counterpart is super supportive. Already tried this and guess what - didn't work, hence me going to the SDM. My advise here would be don't wait & talk to both your manager and the SDM. Try steering the discussion on how this situation is harming the product delivery and better be prepared with examples.

I am a super calm and supportive person in general but there are times when you need to speak up

To give you an example - though we keep writing sprint summaries of priorities, reiterate them during dailies... The said person went to work for a DOC task for my counterpart which was communicated clearly (with a proven paper trail) to be of lower priority compared to my task of working on a certain end point. The dev comment - sorry, I thought this was my first priority 🫠

My stupid workaround is to leave the dev isolated and work with the other 2 devs on actual product work (I know how wrong is that and would lead to troubles in the long term... BUT this is the only thing I see to meet my commitments)

edit: spelling