LX200V50 EVB - Was working for 10 minutes

Hi, I was able to get two WisLink PLCs working fairly easily out of the box. I connected the red white and black wires and was able to get 300mbps speeds right away. However after about 10 minutes of testing they’ve stopped communicating entirely. Is there any troubleshooting I can do or is one of the units possibly defective?

Thank you!