Not to defend Sandra, but remember he's been a "child star" all of his life and that's how he approaches life. He was given always a script of things to do or say. Even the "spontaneous" moments were directed by the show's crew. They might have not been told explicitly what to do, but all their socialization was for the cameras, like: "today, you will buy grandpa a cake and celebrate his birthday!" Sanguine can't operate in life without receiving instructions.
Same way, his only known way of bonding with his family was through those scripts. They didn't celebrate something because they wanted to, but because they were expected. For Sandbag, these activities are things his family enjoys to do and a moment for all of them to be together. That's why he's so mad when they won't help him. He's grew up seeing them perform for the camera, but they won't perform for him. He takes it personal. It's rather sad, actually. Griff, Ari, and Jazz ain't like this, but he is like this. They all, and I mean the parents and grandparents as well, want to put that behind them but Sandal can't and they're all forced to keep doing it.
BTW, other day I watched some videos made by siblings, and it was kinda funny-ish, but definitely much funnier than Sandunga's content. He truly has zero charisma and none of the things they do are interesting or entertaining. No wonder all the content he can do is "here is my family saying trans rights!"