Tab Group Favorites bugs on MacBook Air M4 with Sequoia 15.5

I recently upgraded to an M4 MacBook Air with the latest OS. I've had a couple issues with Tab Groups. I used Migration Assistant to transfer from my older Air and, all data seems to have transferred except the Tab Group Favorites I had saved. The list of Tab Group titles is there but all of the folders are empty. I tried to recreate one by opening up the sites I had saved and, one by one, adding them to the existing tab group (using R click menu). They disappeared and are not where I thought I had saved them--the folder remains empty. I also tried deleting some of tab groups all together and can't seem to do that either.

Anyone else having issues? Any fixes you can share?

Thanks.