What is this red border and background on text box
Hi,
I am using InDesign 18.4. After updating. from macOS 11 to macOS 13 this week I get this red border and background on text boxes in some existing documents. It is only visible in "normal" mode. When I switch to preview mode or when I export to pdf it is not visible. The weird thing is that some documents are affected, and others are not, even if they are in the same book document. Is this a feature or a bug? And how can I switch it off or on?

