While I'm in Bastion's Keep (selling items to Botulph the Miner), my Gargantaun Bruiser will occasionally respawn himself. He collapses into the ground and then reappears. The skill is then on cooldown as normal, even though I haven't manually cast it. What is the cause of this?
1 Answer
"Gargantuan" is a active ability, that is, you have to deliberately cast it.
What you are describing sounds like that is exactly what is happening. Your casting the ability while already having a gargantuan active, so your gargantuan is automatically killed, and another one is summoned in its place.
If you are pressing and button that you normally wouldn't, it is worth checking your control scheme t see if there are any secondary buttons mapped to cast the ability, that you might be inadvertently pressing in your interaction with the vendor.
Other then that, report it as a bug.