What vendor did you use on aliexpress?
In my article they are mentionning a big one (btf-lightning) that is not that good and another one (mokungit) that seems to be reliable.
Another i didnt really understood, it seems the sk6812 replace the ws2812b because they were not really reliable (maybe it was only at the beginning) and that a lot of vendors are selling sk6812 as ws2812b to not flood the market with a lot of different part number since they are really close technology.
So my question is, you ordered ws2812b it seems from your manual and you said you checked they were the right led, you checked the ortie tation of the pad then? Since it seems to be the only different between the both (cf my article in the comments i think)
Sorry for the headache about this but it seems rather complicated to shop.
You can't simply look at the difference in price of the strip from adafruit and aliexpress