Just in the last couple weeks we've had one Fox News personality call for the murder of the homeless on air and another one call for the bombing or gassing of a UN building in New York, again on air.
The free speech the left mostly has issue with is stuff like that, or POTUS publicly saying immigrants are poisoning our blood, or trans people shouldn't exist. And when millions of people listen to them, attend their rallies, and believe their lies you WILL have some who act on it with harassment, discrimination, and violence. We've seen it over and over and it's why most violent extremism comes from the right.
The free speech the right mostly has issue with is being called white supremacists, nazis, and fascists and the consequences they face from the things they say and do by the private and public sector (non government).
That's not to say there aren't examples of free speech issues or violence from the left but it's like 80/20 right/left