HP laptop, windows 10, PM version 6 build 3889.
Using PM 6 for first time.
In image preview with Show Blown Highlights selected, at normal image size such highlights appear in red, as expected.
Click Zoom and the whole image turns red.
Selecting Off (for highlights) allows zoom function to work perfectly.
As I was writing this an automatic Firefox update interrupted me.
After the update the zoom and highlight functions now work fine.
A problem or not?
Paul