During melting on the LightScanner 96 instrument, the intensity suddenly makes a sharp drop, before the expected amplicon melting point. The intensity drop ruins the data.

We have tried several things to correct the issue, and often a plate calibration and a new melt works. But the next run might make the same drop again. 

We have had Lightscanner for 8 years, and have run in excess of 60,000 samples, but never seen this before. We run four different unlabeled probe and small amplicon assays. We use the recommended plates from Bio-Rad and BioFire LightScanner mastermix.

Any suggestion to correct this would be warmly appreciated.