Possibly a gnome issue. I think it was discussed again in the past
The same thing happens in firefox and in chrome as well (and in the rest of the browsers I guess), because I assume this is the right behavior of the exit command on the menu. Pretty much like ctrl+t opens a new tab on all browsers, and thus not an issue.
I am pretty sure you should blame gnome about that. Have you tried using another desktop enviroment along with wayland or xorg along with gnome?
The heart menu is an extensions, like those addons at the now almost defunkt Opera Addons.
It's a more comprehensive case to get the heart menu to talk & command speed dial as those both are extensions...
Mozilla Firefox will likely have solution with this issue as they are making web panels for FF sidebar - but ppl's extension installed on the browser can't affect what goes on at the web panel -> such as ads etc.
I still remember the time when Opera was the innovator and went to meet others: "hey let's make this kind of protocol". But nooo: FF just upgraded they're ext base and already they are making big progress. So soon.
I have Opera 54.0.2952.64 on Manjaro XFCE
I get similar issue with window buttons not shown when maximised
There is a close button to right of tab menu, but nothing is visible except a hover tootltip "Close"
Double clicking in blank space to left of tab menu will restore window size