As a former Product Manager with an inclination towards design I can definitely relate to this. I’ve always had the philosophy that a great Product Manager can understand and balance the needs of design and development. That means at least being able to understand UX issues and prioritize/validate them. The most common example is when a Product Manger ends up making decisions based on wireframes & product mockups that they aren’t able to critically review (especially when a small UX change in those wireframes/mockups could require unexpected amounts of dev time). This eventually introduces all sorts of scope problems when those wireframes/mockups eventually get seen by project managers or dev teams.