I'd try another (maybe simpler) password. Start with a short one consisting of only digits and letters. If that works, make it longer, but stick to digits and letters only.
A few days ago there was a post here of a member who used a password of 64 characters. That's very safe, but he found it too long to type into the TV. So you'll have to find a compromise.
Smart tv picks up router and asked to put in code (do it correctly) then wont connect get same message switch router off and on or check security code. Tried all options but still no connection, CAn anyone help thanks