Broken Link / Gaussian Blur bug

I’ve been experiencing this Illustrator bug for years, and it has consistently behaved the same way.

It only happens when I already have one or more Illustrator documents open and then open another file with a broken/missing linked image. If a Gaussian Blur progress window appears in front of the missing-link warning, Illustrator becomes stuck afterward: the dialogs disappear, but the canvas can no longer be interacted with and nearly all menu commands are grayed out. I can still save using cmd+s, and switch between documents, but can’t interact with anything on the canvas. Can click the toolbar too, but it doesn’t change the cursor.

If the Gaussian Blur progress window stays behind the missing-link warning, the problem does not occur.

It also never happens when the affected file is the first document opened after launching Illustrator.

I am currently able to reproduce this in Illustrator 30.7 on macOS.