My Wired screen mirroring/DeX does not seem to be working on my SM-N960U1(Samsung Galaxy Note 9). Dex works with a laptop.
When trying to connect with wired HDMI to my port I get the error, "Make sure the HDMI cable is connected properly. If this continues, try a different cable," I have attempted cleaning the port, different HDMI power adapters, HDMI cables,I've tried playing music before connecting the adapter, using different TV's, enabling USB debugging, force desktop mode, factory resetting the phone and some of the things below.
Smart View functions properly for both screen mirroring/Dex but not wired.
"Possible Fixes Use an Official Samsung DeX Cable or Adapter - Some third-party USB-C to HDMI adapters may not fully support DeX. Check out this video guide comparing different adapters.(Don't own)
Check HDMI Compatibility - Not all TVs or monitors support Samsung DeX mode. Try using a different HDMI port or a monitor with DisplayPort.(Tested)
Enable DeX Mode Manually - Swipe down on your phone, tap DeX, and ensure it's set to HDMI mode instead of Screen Mirroring. This Samsung tutorial walks you through the setup.(Don't have this)
Clear Cache for DeX Services - Go to Settings > Apps > Samsung DeX > Storage > Clear Cache.(Tested)
Try a Different USB-C Hub - Some users found success with multi-port USB-C hubs instead of direct USB-C to HDMI cables. This Reddit thread discusses similar issues.(Did this)
Check for Software Updates - Samsung may have released a fix for DeX connectivity issues. Go to Settings > Software Update and install any available updates.
Test with Another Phone - If possible, try connecting a different Samsung phone to the same setup to rule out hardware issues,(don't have, one that functions)" - Samsung support.
It may be software that's the problem because the connected device seems to always control the USB. My phone also repeats, "USB connector connected," "USB connector disconnected," "USB connector connected," ... On all the adapters I've tried.
