Simultaneous TNT explosions destroy block item drops

When making a warped fungus farm I have tnt dropping from above to destroy the blocks there are 2 dispensers to destroy many blocks on both sides as the tnt drops it will explode the block and create an item which is then blown up instantly the dispenser are connected together with just redstone dust so there is no repeaters causing this issue. Note this is running on a vanilla server

Here is a video demonstrating the bug on the same server