It's hard being different at school and that's always been the case.
I was teased at my working class school because I didn't have the local accent ( even though I was born and raised there)
I had my parent's posher middle class accent as they never allowed me to developed the cockney/essex accent of my peers.
DH moved from Manchester to Essex as a 10 year old child and had his northern accent violently bullied out of him at secondary school.
We had to move my DD from her school due to bullying. She had been to a lovely middle class state primary school in our affluent little town but as she has a learning difficulty we decided to send her to a well regarded outstanding academy in the neighbouring town as it was known to be supportive of children who struggle academically. School had a deprived catchment area but had great results. It seemed to be a great choice.
We got DD in due to having priority to go to any school of our choosing. A few others from our town got in on sports ability. All of the kids who went there from our primary school ended up moving to other schools due to the bullying. They just couldn't fit in. It wasn't helped by the fact that our town is well known for being a bit posh and full of rich people.
She was teased for having an expensive back pack ( the hard wearing £80 fashionable one that all the kids in our home town had at the time ) We immediately bought her the £20 tote bag from New Look that was the "in" bag at her new school.
She was bullied and called "rich girl" just because she was spotted by some boys being dropped to school in our new car.
She made a friend who after being invited to our home went back and told everyone about our big posh house ( actually just a 1930's semi) so she was teased about that. It then seemed that the other girls felt she needed to be ostracised just for being from "posh town"
There was a big cultural difference between my parenting style and that of alot of the parents at the school and when I didn't allow DD to have the same freedoms that her friends had she was othered. Some of the things I wouldn't allow were for basic safeguarding reasons. County lines was a big thing around that area.
The bullying became too toxic and we moved her to a private school in the end ( there were other issues around the school's zero tolerance discipline policy too - it wasn't just because of the bullying)
I should have originally sent her to the local academy in our town but it didn't have the greatest reputation for SEN support. She would at least have fitted in socially.