diff images aren't always shown. Loading doesn't terminate.

I am using the Vs-code Kogito bundle plugin version 0.21.0 (alpha). When I open a diff view of a .bpmn2 file or .dmn file, I expect to see the graphical form in the old and new state. Unfortunatly, it happens frequently that none or only one of the images loads. Often, only the loading image keeps on being shown:

It seems to me that something is wrong in the timing of loading the image.