Nested tab groups broken in v2.19.1

[mathijssterk]

Since v2.19.1 nested tab groups no longer work. When clicking on the tab with the nested tab group, the top level tab group becomes empty and nothing is shown anymore.

Seems to be caused by #2299 as it still works fine in v2.19.0

Steps to reproduce the behavior:

1. create a nested tab group
2. try to navigate to one of the nested tabs

Demo

See this CodePen: https://codepen.io/mathijssterk/pen/qEWmbpN

Try to visit child tab B2. Good luck ;-)

[niboan]

I have the same problem and did a little research myself before I found this issue. It seems that the nested tab group sets the active tab on the parent, but with the id of the nested tab.

Check the console in https://codepen.io/niboan/pen/gbYebpz

[bennymeier]

We also get errors with the tabs after updating to 2.19.1

[schilchSICKAG]

As we might have caused this bug, we will fix it asap. Sorry, we seem to not have tested it with nesting when contributing it :(.

Handled via synergy-design-system/synergy-design-system#766, will create patches for Shoelace at the beginning of next week. Also adds some overall improvements for the tab handling and the underlying mutation observer, which may also caused other weird behavior so its a (small) win, too :)

[schilchSICKAG]

☀ PR available at #2367