I do DNS Check with F-Secure Router that I got an Amber or Yellow Colour instead of Green. How do I know if the DNS is working or okay? But it says that the check is incomplete.
Make sure that you do not have any VPN turned on as this will prevent the F-Secure Router Checker from retrieving the necessary information. VPNs encrypts the traffic.
For how long (days/weeks) have you been trying to run this check and on how many devices have you tested this out? Maybe a reboot of your router could help but I can confirm that the F-Secure Router Checker worked fine at my end with a green result so there seems to be no issue with this tool.
At my end, i use the cloudflare dns in my router configuration to do the f-secure router check. Somehow it still get a Yellow colour. I did not have any VPN network turned on my Wifi Router. There seems to be a problem with cloudflare dns.