This question is a matter of class struggle. The contradiction between the bourgeois and proletarian united front against fascism is antagonistic.
The bourgeoisie "agrees" with the struggle against fascism only to a certain extent, namely only as long as the capitalist system remains untouched and bourgeois class rule continues to exist undamaged. However, the proletariat only accepts the revolutionary united front against fascism, which combats the capitalist cause of fascism and will eliminate its inevitable restoration forever. The proletariat understands the red world front to mean the abolition of world capitalism and the creation of world socialism. Dictatorship of the bourgeoisie or dictatorship of the proletariat? This is the question of the united front tactic that divides bourgeois-revisionist and proletarian-revolutionary anti-fascism. Comintern (SH)