I've seen it a few times now - that one person on the team that just likes to cause trouble, or cause delays, or just hit the "No" button frantically no matter what you do. The software industry has been going through a renaissance for the last decade or so and the old style of programming in cubicles is a distant memory. All software now is developed collaboratively, and we use team tools to get things done democratically. "All voices heard at the table."
...sometimes.
The problem with democratic processes is that they're also easy to corrupt. Company policy always harps on about "being civil" and "treating people with respect", but it's also easy to be a complete pain in the ass in a very civil way. We had that one person on the team that wouldn't do their work. We went through an entire year of development and ran into crunch because that person wouldn't do their work. That person also wouldn't let me get my own work done, and they managed that by blockading all the development processes and calling endless and senseless meetings that never went anywhere. In the end the team was lied to and the schedules were manipulated to create a crisis. Interestingly enough all the bogus arguments against my work that occurred over the year seemed to melt away in an instant once the fire alarm went off. I completed that work but that's not what the books show. I burnt myself out and ended up in hospital at the end of a carefully orchestrated and manufactured emergency.
HR was less than useful. Of all the information I gave them regarding incidents and lies in meetings they used precisely none of it in any investigation. Instead threw the book at me for being "uncivil". They've dismissed this other person but they're still continuing to pretend that none of it really happened. Gaslighting. They can't admit that anything happened because they have to protect the company.
The losses are significant: plenty of doctors, hospitals, drugs, and time are involved. The job is also gone. Fortunately I'm not facing financial ruin and I can afford to take a little time out to recover. I'll probably have to do that now because I'm on a strict diet of anti-depressants and trauma therapy.
Don't do what I did and try to be the hero. You can not win this fight. If they can't control their rogue employees then the best thing to do is walk away and let that company sink in its own self-made swamp.
Go find a productive company that models itself on your better values.