The only modification I did was to change the "20" in the original Codepen to "200" for both html and css.
Bug 1901190 Comment 1 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
The only modification I did was to change the "20" in the original Codepen to "200" for both html and css. FWIW, till a few months back, this testcase showed the symptoms of bug 1840988 and co and did not crash. Now it crashes but doesnt show those symptoms.