Think it was tyre temp as far as I recall, it was also in the UK in Feb, professional F1 drivers had the same struggles racing in Germany in 2020 (November I think!)
Can't remember to be honest, and I can't even remember if it was an F1 car, I remember a Formula Renault being involved. Fairly sure they cold slicks, but can't remember much else!
Think it was tyre temp as far as I recall, it was also in the UK in Feb, professional F1 drivers had the same struggles racing in Germany in 2020 (November I think!)