I wondered about that as the cause, but in the report extract I quoted the author states she can't explain why such a high proportion of offenders are Asian, so it cannot be that the report was scoped on Asian grooming gangs in particular.
I am absolutely not here to defend white anything (though I am white myself, just for transparency). But I do think that there is a very real institutional resistance to labeling non-white offending as such (e.g. as found in the Jay review, Casey review, IOPC and others). If, say, it was found that a hugely disproportionate share of white sex offending was men of French heritage from a particular part of Normandy, I'd absolutely 100% want to know what was going wrong with the Normans, and to stop it. If that made relations with the French tricky, so be it. Ditto where we find, e.g. white Protestant/Catholic gang criminality, Chinese triad organisations, white British drug trafficker rings, black urban gun crime, white European thieving rings, white paedophile rings, etc. etc. etc.
That doesn't mean I only want to look at things through an ethnic/cultural lens. Absolutely not. Only where it seems to be relevant to fixing the problem. And absolutely not to ignore crime that doesn't fit crude patterns. But there's enough in all we've read and seen about this particular issue to think that specific race and cultural elements were absolutely central to both the offending and the response to it, that I think we should be comfortable facing that.