It seems only the axes containing the colorbar were saved
A topoplot in Brainstorm contains two axes, one for the topoplot itself and one for the colorbar.
As such, you would need to copy all the elements from the topoplot axes to the axes in your subplot
What is it that you are trying to do?
It maybe an easier way to obtain the intended visualization
P.S. By saving a Brainstorm figure as .fig, the interactive behaviour is lost