Yeah man, duds suck.
The last CX650M I bought from Best Buy was garbage, huge coil whine, noisy fan and unstable with my kids i3 8400/RX 470 setup which should use about 200W total. It was so bad I wondered if the hardware was bad... swapped out the CX at BB for a RM750 as a last resort (at the time I think the CX was $75 and the RM750 was $105!) and it's worked flawlessly. All the platform issues with that computer disappeared after fighting with both an old Seasonic Gold unit and the CX. The beauty of buying at brick and mortar though - I had to drive there, but instant gratification and no wondering if some RMA dude at some warehouse would be a dork and deny my RMA.
Glad yours is working well, for the right price I'd buy another CXM unit too

$95 is kind of depressing