Why is my .Touched event not recognizing collision with other parts, but only with my player?

local function destroyParts(hit)
    if hit : IsA("Part") then -- Checks to see whether or not part touched is a part
        print(hit)
        hit.Anchored = false -- Unanchor parts
    end
end

wave.Touched:Connect(destroyParts) 

The part I am using is a Union and everytime it passes through another part - cancollide is disabled - the parts that are touched are uneffected. The anchored property is still checked on the other parts.

I have another line of code that kills the player when it touches the player and that works fine. So what am I missing here?

For information purposes, "wave" is: local wave = script.Parent