I'm having freezing issues as well, but I'm on a Galaxy S8. It most often happens when an external app tries to call Opera to open a link, but it's also happened just tapping the Opera icon to bring up the browser manually.
How many different apps Opera wants me to download? Tomorrow they will release another app called Opera History and will remove history feature from regular app? How far will this go?
Chromium itself is already implementing this, which means within a couple of versions Opera will have it without their developers actually doing anything.
And you posted this under "Other phones"? Moved to Android - though I don't believe there is a bookmarks bar in Opera for Android, so you might consider making a post in Feature requests asking them to add one.
@leocg Yes I know that there is a night mode in Opera but in Opera mini there is still an option to protect the eyes, then the screen filters out blue tones.