Turns out I was using my Note 9's charger. I used the wireless charger's power brick and cable and it worked perfectly. Hope this helps!
I verified that I have the duo's charger connected and it no longer charges my gear s3. It only now always flashes red using either side. My Note 9 charges fine on either side. If this cannot be resolved I'll be returning it.
I have the same issue. I’ve unplugged, replugged, checked the cables. Still doesn’t work. Won’t charge and light flashes red. These things are pretty expensive to only last a couple months. Bummer
Purchased my duo directly from Samsung. It worked more or less in the beginning but now only blinks red after the initial startup. I have tried multiple adapters including the Samsung fast charger and a dozen different cables to no avail so it looks like I have a $100+ paperweight.
It happened to me also - red light blinking (on single wireless charger version for Note 8)
Proved to be a wall outlet issue although that Philips charger it used to work for 2 months without problems. Switched with the original Samsung charger and seems to be ok for the moment at least.