Assume a UI plugin adds a custom sub tab:

  api.addSubTab('Host', 'Custom Sub Tab', 'custom-sub-tab', 'plugin/ExamplePlugin/tab.html');

After logging into WebAdmin GUI, selecting item(s) in "Host" main tab shows the "Custom Sub Tab" header. By default, the first standard sub tab (i.e. "General") is revealed. Assume the user clicks the "Custom Sub Tab" header to reveal the custom content.

Actual results:
After changing main tab selection, active sub tab changes from "Custom Sub Tab" to previously-active-non-custom-sub-tab (i.e. "General).

Expected results:
After changing main tab selection, active sub tab is retained, regardless of whether it's a standard or custom (contributed by UI plugin) sub tab.