Here's how the overflow symbol location appears when the text box isn't selected:
Pretty sure that's a bug.
Try resetting your preferences:
Windows: Start InDesign, and then press Shift+Ctrl+Alt. Click Yes when asked if you want to delete preference files.
macOS: While pressing Shift+Option+Command+Control, start InDesign. Click Yes when asked if you want to delete preference files.
A dialog will appear asking to delete the InDesign Preferences, select 'Yes' on this dialog.
Further info and instructions here if needed:
If a document is not behaving well then try
Open the IDML in InDesign
Save the file as a new InDesign file with a new name
See if the issue persists.
Unfortunately, there's no difference:
Try changing from GPU to CPU preview.
Maybe it's just a preview issue?
Good thought - just tried it, and the symbol sort of appears, but looks like this:
It's dimmed out when the frame isn't selected. That is normal behavior.
It's now visible—dimmed as is expected because the frame is not selected—but also very small. You can increase the size in Prefs > User Interface Scaling > Anchor Points, Handle and Bounding Box Display Size.
As a tip, keep an eye on the Preflight Indicator on the Status Bar—it's the red light, green light button. If you see a red light, double click the word "error" to open the Preflight panel, and use it to navigate directly to the overset frames.
Thanks Barb - my Preflight "traffic light" is always on, but obviously doesn't allow us to visually identify anything.
Am I just imagining that the red plus in the square was always visible in the past?
I seem to remember it being brighter. They might have changed it along with the scaling ability. Works the same in 2022 and 2023.
Sorry, didn't work. (See below also)