I think they(M.R.H) may be mistaken in the labeling
I noticed the flowers they sell come from Egypt
the seed they sell seem to be the true (sabdariffa)
I have grown the sabdariffa from seed several times , never has a red flower
I have also harvested the flowers from a H. acetosella for tea it dose not have nice large calyx
the red flower one(H. acetosella) grown very widely in Florida is often called false rosella
I hope what you ordered will work for your intended purpose