Hello,
I’ve found this Rose, Floribunda/Grandiflora habit. Newer canes or Geiltriebe/Wasserschosse (idk the english equivalent) are a little bit more heavily and classically red-thorned (no small thorns).
Big flowers, outer (or even most) petals are white striped and more purplish changing to a crimson-red towards the heart. They seemingly were holding up well as it was quite hot and sometimes rainy the last days. I haven’t ruled out Gräfin Diana, as the location of this one may offer a little more protection as the one I know. She may have less pressure from other Roses here and thus perform better, but something’s off.
The fragrance was on the stronger site, it’s a Floribunda-like citrus-y smell. Grave is from 2015, if that’s any help.
I can provide more photos but I’ll post the flowers for now.
PS: The second photo is the real Diana, has a peachier fragrance, big and small thorns. The flowers are more filled and she blooms shier than the mystery rose, but those could be site and rootstock differences. It’s also hotter today and the second one is located a few meters higher on loamier soil, the first one might grow closer to the groundwater level.