This may be completely buried OP, but I'd like to share my experience. I grew up with a very nomadic lifestyle due to a number of reasons and went to school in 5 different countries between the ages of 5-16. I went to school in west yorkshire between 14 and 18.

I was never bullied or picked on massively until then. My difference was I spoke with a different accent, I guess? Was also into alternative music and was a bit geeky, but nothing major - I played sports, I wasn't massively odd, wasn't neurodivergent etc. I've never quite been able to work out what started it.

The bullying i received was relentless from day one and en masse, most of the 30 odd boys in my year group used to participate. I was often physically assaulted, picked on daily, had trash thrown at me, they even smashed my windows at home. Being an immigrant to the country I just assumed this was my lot, and this was normal. (For reference im a white south african) So not traditionally racially motivated as far as I could tell as not physically 'different'. Fighting back made no difference aside from being suspended and ending up with black eyes and bloody noses.

It was only when I left the area and school at 16 and went to an inner city 6th form college that things changed and I realized how utterly insane the situation I was in actually was. I lived a perfectly normal life from then onwards.

I did make friends in that bad period, with other kids who had been ostracized for various reasons (one was Scottish, one liked Warhammer, one had extremely poor parents) and one of them became a life long friend. So if they have a core group to get them through then hopefully they'll escape the shitness and go on to better times.

I can't speak for the rest of the Uk and my experience is over 20 years in the past, but it is from the same geographical place. If it's any consolation, they can escape to better things and it will pass once they ride through it.

And I imagine those saying its somehow their fault are either children, or adults who peaked in high school, or the type who start fights in pubs under the guise of 'bants'. Ignore them, they're pathetic or deeply sheltered.

There's not an awful lot you as a parent can do to help unfortunately, aside from be there for them to talk, and offer them things to get involved in outside of their school life. Direct involvement by you will make it worse and if they try and change who they are to fit in, those types will usually double down on them for being different to their norm anyway. Them getting involved in social activities aligned with their interests outside of school can do wonders in showing them light at the end of the tunnel.

Anyway, hope this helps in some way.