This is a big that has been happening to me on BedWars in the North America region. (May happen in other regions haven’t tested it yet)
When you place a turret, it initially doesn’t do anything like it’s supposed to. When an enemy comes to your base, however, the arrows that are fired at them also hit you and deal damage.
I play on a mobile device on the newest version of Minecraft.
Vid of the glitch
Thanks!