The last time I checked Consumer Reports, Porsche was actually on the list of reliable used cars.
In the UK ranks as the least reliable brand: https://www.thecarexpert.co.uk/porsche-named-least-reliable-...
A common trend with german carmakers in recent years. Not good for Europe as a whole.
That data seems to imply there is perhaps another reason for the rankings then what is to be assumed.
I can't say how but it seems to me that may have an influence on their data.