You clearly aren’t doing much to educate yourself such as listening to people talking about things from their viewpoint
the i don’t understand why white lives matter line is amusing. In any reasonable social circles it would mark you a racist and laughable that you and others can’t, or pretend not to see it.
why don’t you wear a T shirt with that on it and see reaction you get from any BAME colleague? Obviously you will have no idea of any offence and can seek solace that oddballs on here will sympathise.