Some router will cache DNS lookup, so some times you may get an error.
Please disable the DNS caching feature on your router, or set the DNS directly on your TV/computer to prevent the caching issue.
On the Services tab, under Additional DNSMasq Options, you can set these 2 options:
From the DNSMasq man page:
Set the size of dnsmasq's cache. The default is 150 names. Set the cache size to zero disables caching.
Disable negative caching. Negative caching allows dnsmasq to remember "no such domain" answers from upstream nameservers and answer identical queries without forwarding them again.
DLink router: depending on the model, please disable the following features if they are available on your model.
disable "Enable Advance DNS services"
disable "Enable DNS relay"
disable "Auto DNS"
disable "Enable anti-spoof checking" from Advanced -> Firewall Settings
From your Windows:
1. Click Start and open Command Prompt ; you will see a black window.
2. Type in ipconfig /release and press enter
3. Type in ipconfig /renew and press enter