About the grad=0, which have 2 continuous zero convolution

in your code in SpatialTransformer Or Resblock,
proj_out will output zero ,then x will be zero
and zero will input to the zero-convlotion in below:

and your persume: x not equal 0 is false
I'm sorry for the inconvenience

Start by locating the SpatialTransformer, Resblock, proj_out, and zero-convolution implementations referenced in the issue, then trace the forward and gradient paths around the two consecutive zero-initialized layers. Confirm the behavior with the relevant existing tests or a minimal gradient check, and document whether the stated assumption about x and gradient flow is valid.

Written by the indexing model from the issue text.