Can't remove chips or charging ports etc

Hi!

So I have a really frustrating matter. I cant seem to remove any chips or anything from a nintendp switch board ive used all kinds of different flux including Amtech and rework stations my previous rework station was cheap and terrible so I bought a new upgraded alot more expensive and when I used it fir first time with some cheap flux I was able to remove the m92t36 for the first time ever since then I’ve not beenabke to remove anything.
I paid like 30 pound for some amtech assuming my flux had gone bad ive even messed around with the temperate by increasing it higher as well as the airflow but it doesn’t seem to remove anything other than burn my board and cause smoking!!

Any suggestions please is my technique all wrong?