That is interesting but getting the behavior seen in DevTools would be very informative.
Another thing might be to see if the issue occurs if you create a new profile and try it in that profile. (Make sure your original profile does not have any open windows; only the new profile should be open.) Creating and testing a new profile will not affect your original/existing profile(s).
Does this happen with Chrome? Firefox? Chromium? Any other browsers on the system?