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Hello and welcome to the forum!
You start with a difficult question, because, as you admit, the pictures are a bit blurred. We have to discriminate between Bibio and Dilophus by means of the shape of the front tibiae. In Bibio, the front tibia ends in a single large spine on outer side with a smaller movable spine on the inner side; there are no groups of spines in the middle. The Dilophus tibia shows an apical ring of 7-9 stout spines and an additional group of 1-4 spines in the middle. The ring is difficult to see, but here are middle spines. Furthermore, I see spines on the pronotum of the male, which is also typical for Dilophus.
According to the Fauna Europaea, you have 8 Dilophus species in France. One I can exclude because of black females. For the others we need an expert! You saw them surprisingly late in autumn...
Let us hope for Theo Zeegers's help to get more information.
Regards, Sundew