The error is very very clear; just change your Linear layers dimensions properly; plus why hard coding the dims like that?
(the error probably lies in this line x_e = self.NN1(x_e))
(Check the attribute nn.linear.out_features) (valid for other layers as well(at least the commonly used ones))

m1: [64 x 1024], m2: [2048 x 1024]

this says that you are having some error in your dimension calculation and matrix multiplication can’t happen; the tip is to use the traceback and fix the dims (and it should look like [64*1024], [1024*1024] or [64*2048], [2048*1024])