Its an issue you can rid off by following below:

Switch From Snap to Official .deb

The Snap build is the most common source of session issues.

Remove Snap:

sudo snap remove opera

Download the official .deb from:
https://www.opera.com/download

Install:

sudo dpkg -i opera-stable_*.deb
sudo apt -f install

The .deb version stores profile data normally under:

~/.config/opera/

This alone fixed the issue for many... you can try and tell if it worked or not. I am most probably sure, this will be working for you too.