i need help with heist

how to play heist. I lose 90% matches of heist in ranked and 100% in challenges and I don't think it's skill issue I'm a decent player and have decent game sense but I can't get my head around heist. The problem is that it seems like opponents respawn time is 0s and their super charge rate is 2x whenever they come they have hypers and supers ready and for context i ban good heist brawlers all the time even then I lose. When we go to attack it takes eternity to respawn, in that interval the incinerate our heist.

So heist mains please give me some tips.