Merge question

On April 9, 2021, Quicken dumped all of my split data for one of my accounts. No clue why. It was only this one account. I have a backup that I made on March 7, 2021 that still contains all the split data from that date and earlier. Is there a way to merge this one account from my backup file with my current Quicken file? I really do not want to lose years of data like that!