Try to change your dns to 8.8.8.8 & 8.8.4.4; if it doesn't work reenter the previous one. Verify in the settings (android tv settings) if there is some permisssion denied and allow them all. Try to connecting using cable.
Go to WiFi settings on Android TV and set both DNS from the same company.
Did you recently update to Android 9? I had lots of different problems, mostly sound, ended up doing a factory reset. Works great now. Just spitballing.
change your network settings manually
A friend had a similar problem. Can you access Netflix from any other devices on the network? Try your phone both on and off Wifi.
If not, they may have blacklisted your IP for some reason. Power cycle your modem or have your ISP support release and renew your public IP.
Is there any updates for your TV? Or try factory resetting it.
What device are you using? and is it Level 1 widevine google certified & does it have a netflix licence? Download the app "DRM info" to check, Both these things need to be on your device for android TV netflix and just L1 widevine for prime and some other apps, if your device is uncertified (mi box is, mecool is but mecool recently got there Netflix licence revoked so it wont work anymore, but prime video ect will with mecool as it's still L1 widevine just no valid netflix key anymore, you can get around this by side loading the mobile versions of these apps
I don't know. My first thought was that you have a VPN installed. Netflix doesn't like that but then I noticed the error code.
Here is a link with some info on that:
https://www.lifewire.com/fix-netflix-error-code-ui-113-4173928#:~:text=Netflix%20error%20code%20UI%2D113%20occurs%20when%20the%20Netflix%20app,app%20on%20your%20streaming%20device.
I don't know if you have all ready tried those steps. Goodluck.