Many images missing/replaced with blue ? in the Help (on Mac at least)

Today I wanted to look at what the help files said about Zones.  And I discovered that most of the graphics (screen shots etc) in that section had been replaced with big white boxes with a tiny blue box with a white? inside, like this: 

This is true in many sections of the help.   This is true in both Accordance itself and in Safari.  Things work somewhat better in Chrome, and better all around when searching for a term (the magnifying glass in the column on the left) rather than the index (the A-Z folder chosen here).

I'm working on a MacBook running Ventura.