Parent acting differently around different people? Ever seen this?

I'm struggling with the reality of the situation. My mother has narcissistic tendencies, and it has always been difficult but I always struggle with how inconsistent she is with everyone..

She'll be harassing her care team with text messages, demands, annoyance. Then call me and have a totally calm and casual conversation like everything is fine. Pretending the things shes complaining about aren't an issue and move on totally.

It makes me wonder if people lie about her behaviour but I know how she behaves. It's like I'm being pulled in multiple directions and I don't know when to believe her and when to not.

She demands my disabled brother stays with her, when we try to co-ordinate a day for him to go away, she cancels it. She starts fights about how he's needed and can't leave.

We take him and tell her he's going away for a night and she'd agreed to it (slight lie) and then she starts texting everyone to demand him home. But meanwhile she's totally calm with me. It makes me wonder what's true. What's reasonable. Whether I'm exaggerating OR the people who care for my brother are.

I had to ask for screenshots to find out if she was really messaging people cause she's telling me "it's nice being alone, your brother hogs the tv"

But she was the one restricting his movement initially.

I feel like I'm being jerked around constantly. I don't know where I stand with anyone.