PMC Silver and gemstone

[Catcher713]

Good evening,
This is my first time asking for some advice and hope someone can help me save this piece.
I have been adding gemstones to PMC Silver as into a clay setting and always try to make sure the table of the stone is down far enough so when fired it does not come out after firing. I fired a piece and after polishing it I put it in my tumbler to finish it and the stone came out. is there anyway of fixing the stone in it to stay put? I have never had this happen in 11 years.
Thank you
Helen