Test server? : 184.108.40.206:443 am4-lvs-test.osp.opera.software
Force stop? : Settings > Apps > Opera => Uninstall & Force stop buttons.
My firewall reports that Opera tries to connect every 6-8 hours.
I "Force stop" Opera but after those hours I always find Opera active.
That means, Opera opens itself just to connect to, ignoring user's command (Force stop).
This issue started after recent releases. There wasn't in the past.
Thanks for your attention!