This has occurred multiple times in my career. I was given a feature to co-lead with another dev, and I always wanted to be cooperative with them. Split the work fairly, try to come up with designs through collaboration. But everytime it seems that the person I'm paired up with does things that I view as toxic or uncollaborative. They would often try to take most of the important parts for themselves and try to leave me with the more mundane tasks. And some cases, they would just redo my work in their own style, without even a discussion on what I could change to more align with their expectations.

Even recently, someone I was paired with do complete a feature try to convince our manager that we should work separately on different designs and see which ones is better. I did argue back in this discussion stating that we shouldn't duplicate work without a good reason. My manager seemed to agree.

Now I'm wondering if this is just a me issue, perhaps I'm doing something wrong? In my view, I'm really trying on building something together, but everyone else seems to be competitive and constantly doing things that rub me the wrong way.

Anyone else have experience with this? Any advice or guidance would be much appreciated.