Two capacitors of same value connected in series and connected to power supply instead of one capacitor of equivalent value for PCB design
Ceramic MLCCs by chance? 

The things have a known failure mode (cracking) which usually results in the things failing short. 

Placing two in series (ideally with different orientations) massively reduces the risk of an expensive in the field failure taking out something important. 

There are so called 'soft termination' parts (All the vendors have their own tradename for these) that are massively less prone to this failure, but they are usually more expensive then two standard ones.

If you google "MLCC Crack" you will find much discussion on this.