on 14-02-2019 23:30
14-02-2019 23:47 - edited 14-02-2019 23:49
on 15-02-2019 00:23
I've turned my wifi off and on.
Tried to reconnect wifi.
Forgot wifi and then connected again with password.
Done a reset by pressing the power button and volume button.
Then power button and Bixby.
Checked for updates.
I've checked my other devices and they all connect with my wifi.
I've not spoken to Samsung yet, I was going to give them a call tomorrow and possibly go down to the shop but they won't be able to see the problem.
on 15-02-2019 06:21
OnePlus 6 (O2 & Sfr), Z3 Tablet (Three UK), iPhone 8+ (EE)
15-02-2019 19:43 - edited 15-02-2019 20:01
There is a couple of things it can be. The chosen authentication doesn't match the routers setting or the password is incorrect with an incorrect lower or higher case character or digit (also be aware whitespace is considered as a valid character). Sometimes the Wi-Fi cache works better if you 'forget' the previous setting completely on the receiving device (the Samsung) and try to create a new connection it sometimes works.
Essentially you want to choose WPA2 mode (auto) and avoid using WPS as it allows you connect wirelessly on the fly, so not the best for security.
It's a complicated subject but in principal it's all about radio channels, encryption and broadcast frequencies (2.4Ghz or 5Ghz).
My answer might seem over the top but I think understanding to some degree how something is meant to work solves at least 50% of the problem.