Created attachment 138232 [details] Should have two vertical lines Don't know what's happening here yet.
The html is invalid - there are more col elements than columns but FF and Opera both render something rather than nothing. Opera's rendering is broken. So not sure we should care.
I am able to reproduce this bug in Safari 16 using attached test case and only Firefox Nightly 107 show two vertical lines while Chrome Canary 108 behave similar to Safari in this test case. Thanks!