Update/"Solution" to it losing your tabs: Remove the extension and they all reappear. It puts all your tabs into hidden when you open the browser again, forcing you to unhide them all manually or just not use the extension.

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It was great until I restarted my PC and lost every single tab I had open and saved in groups.

If you close your browser, you cannot restore session to get them back, they're just gone. So, if you had 100+ tabs open that you were using this to organize and remember for you, it will do the exact opposite of that and entirely reset itself to blank and even delete the groups you created.

Does what it says it does and just that when it's not deleting all your tabs.