How can I restore my pinned Tabs in Safari on MacBook Pro

Safari stopped adding new tabs when I looked at a new site. It now won't open all those tabs, even ones I had pinned and I've tried opening History but it only gives today. nothing previous. Don't understand why there is not a blanket restore all tabs from yesterday. Also, why it would change from all those open tabs to blanking them all out and only option is to somehow manually rebuild. Still don't know if that will restore those pinned tabs.

Already rebooted; tried to restore, but now it is the same. There has to be a shortcut or keyboard combo to get back to that session. Any advice or help welcome. MacBook Pro circa 2020 is device; it is up to date with all software updates.

Especially crucial are those pinned, because I need them for legal background and tax info.

Hope that this is not too long, but any advice and help would be most appreciated. Thanks.Safari stopped adding new tabs when I looked at a new site. It now won't open all those tabs, ones I had pinned and I've tried opening History but it only gives today. anything except today. Already rebooted; tried to restore, but now it is the same. There has to be a shortcut or keyboard combo to get back to that session. Any advice or help welcome. MacBook Pro is device.

[Re-Titled by Moderator]