Sticky table header pops in front of jQuery UI dialog

Opened a quick MR that fixed things locally for me. Note that I did not test what happens with a sticky table header inside of a dialog, presumably it does not work correctly, but maybe we can look at that in a follow-up.

The z-indexes in Drupal are documented → and considered stable.

I'm unable to reproduce this issue on 11.x, .ui-widget-overlay gets a z-index of 1259 and is displayed over the sticky header

Thanks for testing, that's strange, as I specifically tried this on a fresh install. But don't have the time to look into this further, so will close, I guess. And thanks for the pointer to the docs, that's very helpful!