I did ask for a solution...
but, I was expecting inside opera...
lmao, that's interesting ;D
and a nice way to avoid the expected solution XD
welp, guess that tells me there's nothing available yet...
that's unfortunate -.-
hopefully someone can build an extension that looks like the Chrome menu.
(that's including me if I ever have room on my plate, and time to learn, but by that time Opera devs may simply move the Opera menu)
OK, I figured it out. In case anyone else stumbles upon it, here is my solution.
On the About page Opera says that it keeps profile data in /home/user/.config/opera. The Cookies file here is just a SQLite database file, so you can use tools like "DB Browser" to view data and write queries. I deleted everything Twitter-related using delete from cookies where host_key like '%twitter%' and now it doesn't log me out.
I know some sites presume when they see Opera for Linux that it is really Opera for Android set to identify as a desktop version, Not a new issue and nothing Opera is doing at all... only answer is to have a useragent switcher identify you as either Chrome or Opera on Windows.
Go to deviantart, search for "start page" (with and without the space between the words), pick the one you like, download it on your system, modify it so as to fit your needs and then open opera, go to settings > basic > on startup > open a specific page and set it there like so
BTW I'm on Ubuntu 18.04
AND OK so I found a fix:
Right click the place where the image should be.
Near the opened elements, you should find a canvas with a width and height of 264 pixels. It also has a style attribute: "display: none"
Remove the style attribute by double clicking on the attribute and press delete or backspace.
Press enter to confirm this change.
The QR-code should now be visible.
If it doesn't work the first try, refresh the page with Ctrl+F5 and try again.