@burnout426 Yes, just checked. All data saved in local storage of standalone application persists.

@burnout426 Yeah, it works fine that way

Resently I cleared my cache and cookies, after that my local storage stopped persisting through browser restarts.

Also, don't know if it's an expected behaviour, but I see that session files in C:\Users<User>\AppData\Roaming\Opera Software\Opera GX Stable\Sessions are being deleted on browser startup.

Ok, it works now.
What I did:

1. Renamed "Opera GX Stable" folder to "Opera GX Stable old" at C:\Users*User*\AppData\Roaming\Opera Software.
2. Ran Opera installation, it creates new "Opera GX Stable" folder.
3. Moved all the files from "Opera GX Stable old" to "Opera GX Stable"

Seems like some file went missing or something

Ok, it works now.
What I did:

1. Renamed "Opera GX Stable" folder to "Opera GX Stable old" at C:\Users*User*\AppData\Roaming\Opera Software.
2. Ran Opera installation, it creates new "Opera GX Stable" folder.
3. Moved all the files from "Opera GX Stable old" to "Opera GX Stable"

Seems like some file went missing or something

@burnout426 Yeah, it works fine that way

@burnout426 Yes, just checked. All data saved in local storage of standalone application persists.

@burnout426 Unfortunately, that didn't help, all the flags are set the same way and security properties are all ticked

Resently I cleared my cache and cookies, after that my local storage stopped persisting through browser restarts.

Also, don't know if it's an expected behaviour, but I see that session files in C:\Users<User>\AppData\Roaming\Opera Software\Opera GX Stable\Sessions are being deleted on browser startup.