The extra air space might cause the jam to discolor on top (still safe to eat), allow mold and mildew to grow (not safe to eat), and you might lose the seal even though it appears to be sealed now.

You could put them in the fridge or at least use them up relatively quickly while the jam is still in quality condition (you wouldn't want to lose all that work :-)

I did some canning before children and then as they grew we learned how to do more together. Once they were in 4-H and began canning for fair entries we learned about headspace & corrected our methods. None of those early jams, applesauce, jelly, or apple butter failed, but some of our plum sauces had seals that didn't hold. Could have been bumped in the storage & transport back & forth for fair entry or while sorting to select the best.

One year our daughter earned the Ball book of canning as a prize at state fair & we really learned a lot more! Now she's married & canning like crazy doing more things that I've ever attempted. I had to buy my own copy of the book for reference & check if often when preserving whether freezing or canning.

Don't worry about those 1st jars & enjoy this within the year.

I wouldn't worry about it. It's likely the jam will keep just fine. It isn't a safety problem and if a seal pops, you'll know it but otherwise shelve and enjoy.

Carol