I had a similar experience at another national lab. It was a dream job up until a few months in. That was when higher positions were swapped out with new people

I had a similar experience at another national lab. It was a dream job up until a few months in. That was when higher positions were swapped out with new people seemingly overnight whose philosophies were completely different from what the lab had subsisted on. In my department, it was as if anyone who protested anything would be found packing their things the next day. It was insane. I left in less than a year for another job. Part of me wishes I would have been able to pull through, but part of me thinks I wouldn't have had a job in a few months. There's no way to really know. Going there for the first time was a genuinely magical experience. I'll never forget it. At the end of the day, change is good. But more consideration needs to be put in the complexity you find at national labs. I heard great things about LANL during my job. I hope things do improve over there.