In my experience radical leftists will ignore ANYTHING that goes against what they believe. It's all made up, or the research was biased, or that group isn't valid, or so on and so forth.
The only thing I've ever seen make them change was personal experience with the consequences of what they support.
And it has to be personal, if it happens to people close to them, friends or family, it's the friends and family who got tricked into believing the filthy lies.
It's bad enough now that if someone actually changes, it can ruin friendships and destroy families.
Just... radicalization is really bad. Regardless of what is radicalizing.