I have a large InDesign file for a product catalogue, and when opening it yesterday, for the first time ever since I started working on it many years ago, I realized that some images have shifted position. It almost seems like the kind of problems we get in Microsoft Word when moving images.

My images are anchored objects in text. They should not be moving position randomly. They should stay at the place I have assigned to them, even with text reflowing following text changes.

Why does it do this?

Windows, InDesign 20.0.1 x64.