A massive part of the v1.1.x cycle involved porting the game to a more modern engine version for better performance:
Fixed an issue where skills would cancel immediately after activation and corrected archers failing to fire.
The engine was upgraded from 2018.2 to 2020.1 , resulting in more stable framerates and reduced crashes.
Blackthorn Arena v1.1 - God of Wars Major Update ... - SteamDB
Includes a new story challenge and dedicated missions.