Talk:Radioactivity/@comment-64.231.172.163-20160128232619/@comment-27466439-20160129193730

Each element item stores its information in NBT data and Minecraft only allows items with exactly the same NBT data to stack. Once you remove an element tube from a stack of such tubes, the countdown timers become unsynced (especially when taken out of a leaded chest), hence the NBT data differentiates. This is not a bug.