Will a PoE filter fix this?

I've got a Cox Panoramic router, but I'm not using its MOCA. I've got 2 Actiontec moca WCB3000N boxes on each side of the connection instead. Box 1 takes signal from a splitter as it comes out of the wall with the other side of the splitter going to the Panoramic. Box 2 receives the signal down in my bedroom. This setup has always worked great until it recently started shutting off every night suspiciously regularly. Can my ISP shut off moca when I'm not using their router to do it? And would a PoE filter help?

Thnx.