I know it's not a bug, but I created a issue to let this know.
This "change" is very annoying, and lot of users complain about it, so I create an issue for it.
There a a lot of explanation of why users want sidebar only in speed dial or opera pages only in the main thread in opera forum :
- Main thread : https://forums.opera.com/topic/31727/side-bar-for-only-speed-dial-option-opera-60/82
Without it, flow becomes useless as we need to do a complex process to access saved flows on desktop...
I really hope this feature will be back soon,