I can tell you that I have the same issue.
They deny claim if you compare a best flexible rate with breakfast...
Also an advance rate with breakfast is denied.
Because you don't book the lowEST rate... which means without breakfast...
If I remember in the past months they were denying claim when I was comparing a best flexible rate with an other rate even there was no prepaid available on IHG.
It was like that for some weeks than it was working normal.
So maybe at this moment there are too much valid claims so they reduce it by applying the terms strictly.