Tea in general is “astringent,” and that’s probably what you’re noticing.
> Later harvests, lower quality plucking, no shading process, incorrect rolling, etc., result in green teas that are more bitter and astringent, with less umami taste.
> https://www.myjapanesegreentea.com/astringency-in-green-tea
But to find shade-grown, early-harvest green tea, you’re going to be paying a big premium.
You might look into macha, but that’s also expensive.
There are things you can do to improve any given tea, however:
> The temperature of the water is key to controlling astringency … This is why you are always advised to brew Green tea at lower temperatures
> It is likely that the unoxidised catechins in the brew will become oxidised through the aerating process and therefore will reduce astringency.
> An often used trick when brewing very strong black tea for Hong Kong milk tea is to brew the tea with an eggshell. This makes a less astringent tea.
> https://meileaf.com/article/tea-masterclass-astringency/