Deregister Device AND (2) unplugging TV for 1 minute (+holding down on button for 20 seconds) worked for me too. Have to do this regularly for Amazon prime. Samsung should really sort this!! Very annoying.
Anyone with other suggestions? Prime has never loaded on my TV. Just goes back to the Smarthub. I have shut off and on, pushed the power button for 5, 25, and 30 seconds as listed in different posts, Reset the Smarthub, Looked for updates, the TV is not registered on Prime, as it has never been used for Prime, set DNS to 8888, unplugged TV for the night, plugged in, pushed power button, held power button, reset entire TV, tried to watch Prime through the internet app and cried a lot......
1. Switched off and on the TV unplugged etc
2. Done the same for router
3. Deleted samsung account and reinstalled
4. Deleted and reinstalled amazon prime
5. I have 150mbps speed.
6. All other apps working
What's the solution
I live in New Zealand and experiencing the same issues, I have tried all the suggestions here to no avail. Today I had an on line ‘chat’ with Samsung NZ and they said they had no knowledge of the issue, I forwarded them this link and was told US televisions have different software, I replied that whilst I appreciated this I was getting exactly the same issues with a notification of insufficient bandwidth. After a fruitless conversation where I reiterated all other television apps were working perfectly and I had also carried out a total reset, plus Prime Video is working perfectly on all other devises I surrendered as he could offer no further help. Frustrating!
OK so the below worked for me, my device wasnt registered so couldn't deregister it just had a Prime app screen saying wasnt connected to internet.
I went into samsung tv network settings and disconnected my wireless internet connection from my TV.
I then reconnected my internet back to TV and when I tried the Prime App it worked