It happened few minutes ago, I started to fight the boss solo, after the stage when the boss disappears and the ads jump out from the ground - they jumped but suddenly all died in place and the boss did not return to fight. Even that the compass still showed the boss is nearby, he didn't want to return.
I could go elsewhere and fight other mobs or interact with merchant npc nearby - but I was in constant combat mode.
After 10 minutes or more I returned to boss site and he was still not there.
Obviously due to bug I could not just log off - due to the stupid "combat mode" restriction - so had to quit the game.
Edited by Gargath on September 19, 2018 9:37PM PC EU (PL): 14 characters. ESO player since 06.08.2015. Farkas finest quote: "Some people don't think I'm smart. Those people get my fist. But you, I like."