Hard perfofmance issues and unexpected disconnections on specific map?

Report ref. number: 1145 872 471
Map: Arachnid Nest t16
Map content:
-Syndicate
-redeemer influence
-Watchstones: Additional exiles; Possessed monsters drop rusted scarab,additional tormented betrayer; Monsters that heal(watchstone); quantity/pack size in unidentified maps
-rest unknown(unidentified map)

I've just entered a map and right after seeing first monsters my fps went crazy. It was just freezing for 3-10 sec with not even a second gap. I've killed syndicate assassins but nothing changed. After few freezes unexpected disconnection occurred, soon later another one.

Killing fortification members finally fixed problem - game went back to normal except my hideout instance no longer existing and me being unable to go back to this map.

Syndicate haven't caused any performance problems in this league until now and my pc was already running a lot more performance heavy content so I doubt it being hardware issue.