Yes! Quite a few time in both
Disneyland and WDW.
As a POC, I have encountered racist guests and racists CM.
To those of you who say CMs are saints, shame on you! They are no saints. Disney just hire anyone who is willing to work for a minimum wage. They don't care who you are and definitely don't care if you are racist or not.
Here are some experiences I had in Both resorts.
Disneyland:
I was in line to meet Mickey on Main Street, one of the CMs that is assistant Mickey decided to relocate to another spot. While walking towards the other spot in line, a Caucasian male and his daughters decided to cut me. I told him I was in line, he turned around and said I didn't see you get in line. A CM was standing right in front of us and decided to look the otherway and told me good luck.
I had a FP for Indiana Jones for 8:15 and I went up to the front. The CM looked at the FP time and told me I am 30 sec early. He directly me over to the side and let the Caucasian family behind me go without even looking at their FP return time.
WDW
As I was leaving the park, a CM approached me to ask me to take a survey. I said no thanks and she replied I'm sorry I didn't know you didn't speak English.
I was walking to the end of mine trains FP line, the CM let the Caucasian couple go to the FP line and stopped me. She looked at me and told me to merge in with the regular line then continue to allow others behind me to go through the FP line.