This is the problem. When Kaepernick took the knee he was booed for being unpatriotic, and called a ‘son of a bitch’ by the president. More people then followed that lead.
The people who booed, said it wasn’t to do with them being racists, but because he was disrespecting the flag, and he should protest in a different way.
When Black Lives Matter became a slogan (before there was any real known political associations), people shouted that the slogan really meant that non-black lives don’t matter, and the slogan should be ‘All lives matter’, so they should change the slogan.
Now, England players take the knee, and the public are sold a lie about it being entirely to do with BLM as an organisation, and are then booed by people saying, we’re not against anti-racism, but we don’t like the political association, so you should change (or stop) the gesture.
If a new gesture or slogan comes into play it will also be deliberately misinterpreted and linked with something else, to give people a cover to oppose it. All of it, sends a clear message to black people, to get back in your box and behave in the way we tell you to.