Run editing/execCommand/create-list-with-hr.html In the DOM you'll see ul > li > hr, but the hr doesn't appear in the same position that it does if you load ul > li > hr in a static document, and the horizontal rule appears before the list marker in the render tree.
It is reproducible in Safari 15.5 on macOS 12.4 and it matches with Chrome Canary 105 behavior. I took the test from Chrome repo and changed it to following JSFiddle: Link - https://jsfiddle.net/q0gveod3/show Firefox display "horizontal line" after unordered list while Chrome and Safari do it before. I am not clear on web-spec here as well, might be topic of InterOp 2022 (of execCommand). Thanks!