Is there any chance that you are missing subtle differences that may affect how you come across as unacceptable and others come across as fine? Timing, tone, facial expression, etc can have an impact on how something is received.

For example - a TA I had in university thought she was being funny when she told our group that we had no excuses for being late... Even if our cat died. Guess who had put their cat down the previous weekend? That would be me. Due to circumstance I did not find it funny in the slightest and it impacted my entire perception of her.

I'm not saying that you are missing those subtle differences. I wouldn't know as I've not been there! That said, maybe there are some subtle differences that you haven't been noticing.

That's the only thing I can think of to even suggest looking at. I'm sorry that you've had to experience so much of this treatment!