The same people who are upset at Jo Jorgensen's support of Black Lives Matter because of the ideological associations of some of its founders are also people who saw the murdering socialist dictator Nicolas Maduro nearly lose his grip on power last year, and rushed to his defense.
Pro-tip: if you defended (or continue to defend) Nicolas Maduro (or Evo Morales or the Castrista dictatorship), don't try to bring up Marxism as a reason you don't like BLM. You stood with Nicolas Maduro, and now you want to screech about how you don't like Marxists? Go to hell. You have no problem with Marxists.
Ironically, most of the people saying that the phrase "black lives matter" is always code for Marxism because those who coined it were Marxists, and that the phrase "anti-racism" is always code for believing the entirety of critical race theory... wholeheartedly reject that "all lives matter" could be considered dismissive of valid concerns in context because words actually mean what they mean.
My advice for the sloganeer-philes? If you think a word or phrase is being used as a code for something else by the person using it? Ask, and try to give the benefit of the doubt in a difficult conversation. You'll find that most people who use ALM and associated language aren't using it as "dog whistles" for racist messages, and most people that use BLM and associated language aren't trying to promote Marxism or the entirety of critical race theory.
The conversation is complicated, and oversimplifying it all into nebulous shorthand phrases and then attaching a whole complex worldview to everyone that uses a counter phrase can be pretty counterproductive to communication.
Also, for your sanity... stay off Twitter as much as possible. That thing's a sewer.