Repro script is attached. Disabling blink-cursor-mode is not a hard requirement, but it makes the bug easier to see. The font and face customizations are both necessary. 1. emacs -Q -l nocursor-repro.el 2. Type 'asdasd' (without quotes) 3. Move point to either of the 's' chars 4. Create a new frame with 'C-x 5 2' The character under cursor won't be visible - just a blank cell (the cursor is blank as well). Then I move point with e.g. C-f and it's visible again. Switching between the frames (C-x 5 o) will make the char again invisible, as long as the point is on an 's' (in this specific scenario, that is). And only in the second frame (or others created later) but not the first one. This only happens on my macOS machine. The face customization is a part of a 3rd party theme (tango-plus). I'm pretty sure the :inverse-video customization should be a no-op but it isn't. Seems like a subtle bug somewhere. As a user of the theme it's taken me a while to narrow down the problem, so it'd be great if someone could look into it. In GNU Emacs 30.0.50 (build 3, aarch64-apple-darwin23.3.0, NS appkit-2487.40 Version 14.3 (Build 23D56)) of 2024-06-04 built on dizzy.local Repository revision: 43c354a0004145c04bbc6adf0cfaa8c21403ad8c Repository branch: master Windowing system distributor 'Apple', version 10.3.2487 System Description: macOS 14.3