Lid popping when I checked for seal the next day I made peach chutney yesterday, hot ingredients into hot sterilized jars.  Wiped the rims. After submerged in boiling water 20 minutes, and sitting placidly on counter all the jars popped but one.  Today when checking the seals, depressing the center of lid, the one that had not popped on its own, popped.  Now I am not sure if the seal of that jar is good.
Is it OK to store it, or should it be used and refrigerated immediately?
You should either store that jar in the refrigerator or reprocess it with a new lid.
The vacuum formed is not going to be as strong as your other jars and may be temperature sensitive. It may stay sealed on the shelf, but it may not. I wouldn’t risk having to discard the whole jar.