Hi Gloria,
It is unfortunate to hear about such an issue, I do have a few questions to let us start:
1. How many parts have you tested in total so far and on how many of them have you seen this problem?
2. What exactly does the first picture represent?
3. Have you tried to desolder "faulty" parts from your PCB and use a multimeter to check their output?
4. Does it happen right after powering-up the board or later during the use?
5. How were the parts soldered on a PCB?
6. What is the complete marking found on the top side of tested parts?
7. Were they purchased directly from us or from an authorized distributor?
Best regards,
Tomas