[1.1.5] Bandit Lord did not spawn

[gimmethegepgun]

The Bandit Lord in Unknown Tunnels did not spawn, as such I could not complete Trapped in either way. Was not stealthed/invisible either, I attacked the other bandits without him showing up, and then moved over every tile without running into him.
Character was Skeleton/Berserker, was wearing Cloak of Deception.