Wording from the FIA regarding the ruling :
Supposedly, this is where Aston's wing failed the requirement. The wing produced different results while on-track compared to when tested by the FIA because its deflection characteristics were altered by "secondary parameters".In a still valid technical directive (TD34) from the FIA, it has emphasised that there are certain behaviours that will not be tolerated even if wings are passed as legal in the pits.
In the note, the FIA says that it does not consider legal “designs whose structural characteristics are altered by secondary parameters, so as to produce (whilst running at the track) a different deflection characteristic than when stationary during the FIA checks. Examples of secondary parameters could be temperature, aerodynamic load etc.”
What those "secondary parameters" would be in the case of Aston is not something we know as it wasn't disclosed in detail.
Nevertheless, Aston's problems run deeper than just a denied flexing front wing. At most, the front wing fiasco is maybe giving McLaren the last tenth or two to consistently be in the fight for wins. It's not the only thing that accounts for the entirety of their current performance level. You can go back and check onboards from McLaren's car in Bahrain testing 2023 and their front wing was bending quite significantly even then, yet the early-spec MCL60 was probably the 8th-9th fastest car on the grid.
