@rejzor Same here on openSUSE Leap 16, opera-stable RPM.
It always start like you described , shrinked window in the middle of the screen.
Really nonsense when other browsers Chromium-based naturally memorize the last window size and position.
Do more on the web, with a fast and secure browser!
Download Opera browser with:
- built-in ad blocker
- battery saver
- free VPN