instance amounts that arent a power of 2

[Milk-Drinker01]

Hello,
I am creating a version of this that works by "painting" instances much like unitys terrain system, but for HDRP. when im dealing with instance numbers that != 2^n, where n >=11, my instances are flickering in and out of existence and acts very glitchy in general. what is the cause of this, and whats the best way of going about fixing it?