As I understand it, X is avoiding to pay fines in Brazil, so in retaliation, Brazil ordered X to be blocked in Brazil if they don't respond. Starlink refused to follow along with the X block, so fines have been imposed at Starlink as well, for not following court order. I'm guessing the fines would accumulate daily, so now Starlink is adhering to the block.

Add in a bit of personality dramas, corruption and typical billionaire and politician bullshit and you have the full picture.