Im pretty sure rarity is bugged

i just got 1 divine and 3 uniques , vaal , alch and few ex on 34% rarity map with no quant (1 div and unique from a boss but this is before the boss loot update so i wont count that as boss loot) t8 map . meanwhile my high rarity maps i get like 2-3 ex and sometimes vaal or alch (like 1 in 4)

my rarity is 77%