Using the sidebar in a saved tab group, I closed several tabs by clicking the 'x' next to their title. Then I quite Orion and re-opened. Those closed tabs were still in the list of tabs on the sidebar. I believe the tabs were greyed out and 'asleep' when closing
Tabs to remain closed.
0.99.126.1-beta (WebKit 618.1.2)
Sonoma (14)