Mitmproxy ignores VPN? - No, works it ok, but a browser was not updating the page

I am running mitmdump on my user account, on MacOS.
I have configured the Firefox browser on the same account to use mitmdump as an HTTP proxy. Everything works ok, I can see requests are passing through mitmdump.

Now, I am switching on a VPN (NordVPN to be precise). Requests are passing through mitmdump OK, but: my external IP address remains the same - NG (I am using to check). I expected it to be changed to the address of the VPN seerver - OK.

If I remove proxying through mitmdump from the Firefox - my external IP address changes to the address of the VPN server (OK).

Changing the start order (the VPN first, mitmdump the second) does not help.

Question: is there some (easy, preferably) way to make mitmdump to send the outgoing requests through a VPN?

Answer: Mitmproxy / mitmdump seem to work OK and do respect VPN. It was Firefox not renewing the page after “Reload” (sorta obvious thing to check first, but I was too used to Chrome, which was ok, showing a change in the IP address immediately after “Reload”).

So: no reload, close the tab and visit the site again to get the current external IP address.