​Prior to the 4.0 patch, Space Marine 2 was fully functional and I played the game for 100+ hours. However, upon the 4.0 patch being released on October 17th 2024, I can no longer play the game.
When the game is booting up under any circumstance, including bypassing Steam to launch purely through the exe, it will completely freeze upon reaching the 'Epilepsy Warning' start-up section. Even plummeting to 0% CPU/GPU usage

However, for whatever reason, Alt Tab'ing out of the game causes it to resume running as normal, with 0 performance or stability issues. I have tried numerous methods to work around this (Disable Steam+Nvidia Overlays, Run in Fullscreen/Borderless/Windowed, close all other programs minus Steam, reinstalled and updated Nvidia drivers etc), but nothing changed what occured.
Until. I unplugged my keyboard. The game the runs perfectly smooth and even boots into the primary hub within the ship; but will completely freeze again once I plug my keyboard back in.
I have seen people on various forms and social media posts state the 'Corsair iCue' causes this same issue for others, and while I do use a Corsair Gaming K55 RGB Keyboard, I have done complete computer wide-scans of both SSD and Hard Drive, as well as my own search through AppData, Program Files and Roaming, yet not a single file pertaining to Corsair is anywhere on my computer. 
Due to being unable to have my keyboard connected to my computer while Tab'd into the game, I am unable to play it whatsoever, nor can I acquire my KSIVA, and have been since previously mentioned 4.0 patch. I have attempted to play again, repeating the methods mentioned above on every single patch since October 17th, but there has been no change in this error.