Kernal level anticheat systems all tend to not recognise each other for what they are, and instead see their "rivals" as malicious software that could potentially be an outside program that gives you an advantage, so the Vanguard anticheat is most likely what caused your issue.
It's like having Norton, Total AV, and McAfee antivirus software all running at the same time - they'll all detect each other as malicious files and get caught in a loop trying to delete or quarantine each other. I had the same issue when I tried having Delta Force and PubG on the same system - the PubG anticheat would make the game hard crash and other programs (like browsers or discord) would follow suit, the Delta Force one would constantly bluescreen my entire system and almost cause some hardware damage due to the amount of times it did it.