So I just upgraded from a Note 10+ to a S25 Ultra and I'm having a significant issue.
I use Dex every day and my setup is a USB-C to HDMI adapter that has USB inputs, plugged into a monitor. Keyboard and mouse dongle is plugged into the adapter. When I plug in my S25 ultra, Dex kicks on but after a few seconds, the monitor starts blacking out and eventually says "no input" and keyboard/mouse sometimes work.
I also have an S20FE from work and still have my note 10+ and they both work flawlessly with this setup. I have to send the Note back for trade-in shortly and my new work phone will not be a Samsung so I need this to work on my S25.
Anyone have any ideas as right now I am Seriously regretting buying this phone.
It sounds like your USB-C to HDMI adapter may not be fully compatible with the S25 Ultra, even though it worked fine with older devices. The S25 Ultra could have different power delivery or signal requirements that affect how DeX functions with certain adapters.
Check with a Different Adapter or Dock: Some adapters that worked on older Samsung devices may not be fully compatible with newer models. Try using a Samsung-branded DeX adapter.
Use a Different Monitor or HDMI Cable. Try connecting to a different monitor or using another HDMI cable to rule out a compatibility issue.
Check Power Requirements. Some adapters require external power for stable DeX performance. Try connecting your Samsung charger to the adapter’s USB-C PD port if available.
Test Wireless DeX. If possible, try Wireless DeX on a compatible display or PC to see if the issue is specific to the wired connection.
