https://www.curseforge.com/minecraft/mc-mods/treasure2?comment=484

Quote from AzarinEvil >>
Found a strange little glitch regarding the key ring and the extra utilities 2 Bag of Holding. If it the key ring is in your bag of holding and you open a chest, it will attempt to put the key ring into the hot bar slot you are using. I would assume it is a result of the auto search function of keys in the ring, but it occurs with vanilla chests too.