Yes, i too am trying to prevent my table header getting split into two pages but it does nothing ...
i tried every combination of page-break-before after, inside on every element here, thead, tbody, tr:first, all of them .... the behaviour doesn't change, literally stays the same no matter what i do.
every thread regarding this is 10 years old and the project repo on github has been archived indicating the project is discontinued
and so, in 2024 we don't have a reliable html-to-pdf generator
wtf, really