Can't login in Headless Mode

[Baseult]

I can successfully log in using Python and the Undetected Chromedriver in headless mode.
Unfortunately, when using this C# project in headless, I keep getting the following warning at the login screen on (https://auth.riotgames.com/login):

Without headless mode its working fine, but as soon as I use headless mode I get that warning.
It appears that they have some way of detecting that.

Given that I'm using the same undetected chromedriver.exe as in python, how is it possible that it works with python but not with this c# project?

Edit: I found the issue:
I had to change options.AddArgument("--headless); to options.AddArgument("--headless=new");

had the same issue with python before see:
ultrafunkamsterdam/undetected-chromedriver#1141

[fysh711426]

You can try it.

using (var driver = UndetectedChromeDriver.Create(
    ...
    headless: true))

[NCLnclNCL]

You need patch with old headless