Why isint my previously bleached hair lightening? HELP

A few problems here.

Don't use quick blue, it's rubbish and causes a lot of damage for how much it lifts (not a lot). Find a brand like Blondor or BlondeME which lift a lot better and are less damaging (only less though, it's still very damaging like any bleach but you get more lift payoff).

As you have Asian hair, I'm afraid you likely have a lot of red to bleach through. The yellow in hair is the hardest to lift, and that's why it's always last, but if you have a lot of red then you have to get through that first to get to the yellow. I'm lucky, I have hardly any red in my very dark brown hair so it lifts to yellow a lot quicker than you'd imagine, then it has so much yellow it takes ages to get through that stage! There's so much yellow that I can't get to the proper pale yellow for proper white hair. My Japanese friend can hardly get past the red stage into yellow without destroying it, so can never get lighter than a mid blonde. It's the luck of the draw sadly.

Now, for your sample. Was it kept warm or did you leave it on the side so it went to the room temp? If it was left at room temp that's not warm enough. Bleach needs body heat to work. If it was warm, definitely dump the quick blue!

Thank you! I'll try another strand test and keep it warm and if that doesn't work I'll try the brands you recommend. I'm new to the whole bleaching and this helped so much!

Please, please, please, just dump the quick blue. It's not capable of high lift bleaching. The others I mentioned are. I wish I'd been more obvious in that before! Trust me, all seasoned bleachers have been through a quick blue stage and come out of it either never light enough or a complete mess getting it light enough. Use one of the quality ones that are MADE for high lift and you could have made it in one bleach rather than two or more. People who think their hair is hard to lift are often using crappy bleach powder. It's always better getting it light enough in as few bleach sessions as possible. It really is worth the extra cash and they aren't that much more expensive anyway.

I also forgot to mention, you need to leave your hair at least a month between bleachings. I know people on YouTube do it several times in a row and appear to have little damage. Yeah, look at their other videos and see just how many of them get their hair cut short not long after! You really need to leave it a while to really see how much damage has been done before adding to it.