S1 images not collected as planned?

I occasionally monitor the planned acquisitions page from ESA for upcoming images. I noticed that in some locations, images are not collected, in some cases leading to months long gaps in coverage. I realize these are planned acquisitions and not actual but is there a location where ESA posts an explanation as to why they did not collect an image as planned?

Planned acquisition can be dropped due to SAR instrument unavailabilities, these are listed in the cyclic performance reports:

That seems to have quite a bit that should answer my questions. Appreciate you making me aware of it.