Do more on the web, with a fast and secure browser!
Download Opera browser with:
IMHO logs looks fine, can't find any errors.
Logout and log nor help.
I know where sync data should appear 
For me it's look like problem with sync on mobile devices. iPad and android phone can be found on device list here https://sync.opera.com/web/ but can't sync anything.
Is there any posibility to check sync logs on mobile?
I'm logged in with Opera Account on my laptop (Opera 40.0.2308.62), Android Phone (Opera 37.0.2192.105088) and iPad (Opera Mini 14.0.0.104835).
Most data appears here - https://sync.opera.com/web/.
No synchronized data on devices (no bookmarks, no speed dial, no open tabs).
Any ideas?