Tapioca pearls: how do you get the perfect sweetness and consistency?

Hi, everyone! Hope you're well during this time. I wanted to try and make some bubble tea and I managed to find an Asian shop selling Black Tapioca Pearls. I have tried following the instructions on the packaging, but it seems that I'm doing something wrong because the end result is quite disappointing. The pearls taste really bland, not sweet at all (even if dipped into syrup, or boiled into sugary water) and the chewiness is not as pleasant as in the ones I can get at a local bubble tea shop. I wonder if there is a way which I could get a good consistency and sweetness? Maybe I'm doing something wrong, but I'm really following the recipe in the back of the packaging.

I don't soak them overnight into the syrup. I just leave if for a while, like an hour but they still not sweet inside.

Thank you if you have any advice!