When there is an active tome of alkahestry in the inventory, full stacks of redstone or redstone blocks in the inventory, and the same item in an itemstack on the ground in reach of the player, the alkahestry tome charges without consuming redstone.

using reliquary 1.16.3 - 1.3.4.1061, direwolf20 1.16 pack in the ftbapp.

Tried to recreate this, but I am unable to with Reliquary. I am not 100% clear of stack within a reach (how many blocks away / is player picking the stack up, ...), but this sounds like some other mod is causing the issue. If you can figure out which one it is let me know and I will take a look if there's anything wrong on Reliquary side.

no additional info provided for a long time so closing this