Pictures do not update when overwriting source files

Hi, recently Rhino (8, Mac) stopped updating pictures when I overwrite the source file. I heavily use other software (Illustrator or Photoshop) to edit image files and place them in Rhino. The default behaviour used to be that if I save the file in the other application and then switch back to Rhino, the picture surface would update automatically. Now it doesn’t do that anymore. RefreshAllTextures does nothing. Closing and opening the file does nothing. Even going into the texture dialogue and choosing the file again does nothing. The only thing that works is closing Rhino altogether and restarting and reopening the file.

What is weird, however, is that the preview in this dialogue shows the updated picture – it just doesn’t translate to the representation in the viewport (see attached screenshot, notice the blue elements in preview but not in the viewport). So I am assuming this is somehow undesired behaviour. Any ideas why this is happening?