Fast.com detects my ISP address

[Thebrynn 1]

just a question for my understanding.

I have the airpvn tunnel active on my router, and all router goes through the router.

Everything on the internet shows my airvpn address, there is no rtc leak etc.
but when I go to fast.com to check my speed, it actually notices my true location / IP address. Just wondering how that is possible.

I do have an unbound setup where your public ip acts as a dns, but not sure if that is how fast.com finds out about my location. (will see if I can force it to go through the tunnel as well and see if that solves it)

Follow up question then would be, am I at risk for others to use that same technique, and how can I mitigate that risk?

Thanks in advance!

[Thebrynn 1]

forcing my unbound traffic through the tunnel does not change anything apparently

[SumRndmDude 22]

I had a not dissimilar issue where ipleak.net would show my ISP DNS servers and occasionally my geographic location. However, it was only when I opened it in Firefox. Chrome, Chromium, Edge, all showed Air's DNS servers and location of the server I was connected to. It was something cached in Firefox because I deleted the cache and forced a reload of the page. Seems fixed now. So have you tried multiple browsers?