The title is a bit confusing so let me explain. Basically, if suspicious sand has a high amount of the same item (for example: 64 netherite ingots), it doesn't give all 64 of the netherite when brushed.

To replicate:

1. Run this command:

   /give @p minecraft:suspicious_sand{BlockEntityTag:{item:{id:"minecraft:netherite_ingot",Count:64b}}}
   

   You can also do

   /setblock x y z minecraft:suspicious_sand{item:{id:"minecraft:netherite_ingot",Count:64b}}
   

2. Place down the suspicious sand and brush it. Through my testing, it seems to give around 13 items instead of 64

Also tested with other Count sizes and the bug still persists, however at lower numbers like 8 it seems to give the full amount.