Interesting workaround and thanks for going out of your way to confirm this.
My alternative solution so far is to paste it into Edge as it formats and color-codes the xml.
Let's hope the devs fix the detection flags in the future.

When you navigate to a feed xml it opens personal news. No view source or anything as it's part of the browser ui and not a page.

I need to debug an RSS feed by looking at it's final generated source. Impossible thanks to opera's newsfeed handler hijacking it. A flag to disable built-in news handling or a simple view source button on the news preview page would save from the need to open another browser.

Found this flag: chrome://flags/?search=news#news-feeds-page-action

Unfortunately it doesn't stop feed urls from being handled by the news reader.

Here's an alternative approach that might help you if you are using Windows:
Get autohotkey from http://www.autohotkey.com/

Open notepad. Paste the following text (excluding the --code sections) and Save as operaPowerMode.ahk (note the extension)

--code start

WinActivate, Settings - Opera

SetKeyDelay, 250

Send, {Up}{Up}{Down}{Down}{Left}{Right}{Left}{Right}ba

---code end

Open settings in opera. Find the ahk file you saved earlier and run it.

I get this nag-bar on every tab at every startup since the last couple of developer channel updates including 32.0.1899. The bar has a Learn more.. button which leads to a useless SSL help summary page. Searching all over the web does not return information on this specific error for me.

The only reason I can think of for this would be that I have a server on my local network which has an FQDN: example.com by which I often access its https pages. FQDN is rebound at router dns level to point to a local network address of 192.168.1.10 to avoid the need of hairpin NAT rules.

Has anyone else experienced this behavior and what are your thoughts on this matter?