My WIFI was bullet proof for many months, then some problems connecting became common. I finally rebooted the TV via system/support/reset in the TV's menu selection, and it seems to have solved the problem. If this were to fail then reseting the Smart features would have been my next course of action.
If the software is up-to date, you have completed a factory reset on the TV, have reset the router, have contacted the service provider and you still cannot connect to the internet; then we would recommend having a technician look at the unit.
I tried changing my password to something shorter and easier and the second i did that, the internet only on my Samsung tv didnt want to connect. I googled for like 2 weeks straight and none of the solutions worked for me.
So in the end I decided to switch the “IP settings AND DNS Settings” back to “Obtain Automatically” (in IP settings on the tv)
Then I went to the Configuration site that is on the back of your router (http:// something something) and turned on the GUEST Wifi option. Gave that a new password and VOILA! Finally after a good few weeks of trying to figure this issue out.
Everyone on google had the same answers and nothing worked for me. Hope this helped someone!