Can I restore missing Mac Safari Tab Groups by resynching from my iPad?

My Mac version of Safari (14.4) has somehow lost the entire contents of its Tab Group Favorites list. The Tab Group titles are still there, but the contents of each Tab Group is empty; ie clicking on a title does nothing except rotate the disclosure symbol by 90 degrees.

The Favorites list on my iPad however is still fully populated. Is there any way of forcing a resynch between the two devices so that the full list on my iPad repopulates the semi-empty list on my Mac ("semi-empty" because the titles are still there). And if I can do a resynch, how do I guarantee that the resynch is FROM my iPad TO my Mac, so that I don't end up with two empty lists?

TIA Howard