No. No it wasn’t. Antifaschistische Aktion was a paramilitary wing of the communists, fighting both the social democratic Iron Front and the Nazi Sturmabteilung.
The only way in which it could be said to be allied with the Nazis is that both of them opposed the social democrats, but the enemy of your enemy is not in fact your friend. The KPD saw both the SPD and the NSDAP as fascists, rather than in any way allying with the NSDAP against the SPD.
Well actually the KPD and the NSDAP did work together as they saw the SPD as their combined enemy.
https://etheses.lse.ac.uk/4102/3/Daycock__KPD-NSDAP-Weimar-Germany.pdf
Here is a PhD thesis to the topic.
Edit: I did not mean literally all the time, one single time before the NSDAP rose to power.
See @jerdle_lemmy@lemmy.world’s comment below
Bro I literally linked a PHd thesis