Region3 not working when fully inside of a part

my placement system has a collision system, so you cant place multiple items in the same place. it works, but if the region is fully inside of a part, it doesnt detect anything. here are 2 screenshots explaining my problem
image


heres the script:

local region2 = RR3.new(hitbox.CFrame,hitbox.Size - Vector3.new(0.25,0.25,0.25))
		local parts2 = region2:FindPartsInRegion3()
		for i,v in pairs(parts2) do
			if v.Name == "Hitbox" and v ~= hitbox then -- checks if the hitbox detected by region3 is not the hitbox of the item currently being placed
				table.insert(boolTable,false)
			end
		end
		if not table.find(boolTable,false) then
			canPlace = true
		else
			canPlace = false
		end