Client IP not updated, cached in browser?

[Network Gal 0]

At http://ipleak.net, the top section "Your IP Address" should alway display the same client IP addr as the lower section "IP Address details", is that correct?  

I have a case where I load the page, then enable a VPN that routes all traffic through a different IP, then refresh the page.  The top "Your IP Address" still displays the *old* IP address, meanwhile the lower "IP Address details" shows the correct updated IP address.  I tried 1) refresh the page fully -> still shows outdated IP addr, and 2) open page in a new browser -> shows correct IP addr.

So it appears something is caching the old IP addr in the browser or cookies, etc.  

Please let me know if I've misunderstood the feature.  It does seem that the same info should be displayed regardless of browser as long as there is no browser-level routing or proxy involved.  Thanks a lot for any help!