Firefox Focus/Klar: what does the leaked “inte…

I use Firefox Focus together with a VPN and what I see being leaked (WebRTC Leaking) is apparently some “internal” IP address provided by my VPN (10.XX. …). Should I be concerned about this? What does it reveal about me? If this is something to be concerned about, what similar alternative browser would be the recommendation?

I also use Brave and this IP information is not displayed when fingerprinting protection is turned on. However, I like focus due to its speed, simplicity and the fact that it doesn’t keep any website I visit by open forever, nor does it save it in the history, so I’d be looking for something similar lightweighted like Focus, rather than a full-fledged Firefox.

Found here