PIPs are just CYA for HR.
I can’t speak to these specific situations because I wasn’t there but when managers speak about “performance” they’re using a euphemism for their perception. This can easily feel like racism because it comes from a place of discrimination.
“I have friends who are x” is a common refrain of racists so isn’t a defense, especially in an asymmetric power structure. Maybe you aren’t, or maybe your employees feel you are but they tolerate it to keep their jobs.