Also mentioned in https://forums.opera.com/topic/86200/alt-enter-in-address-bar-no-longer-opens-a-new-tab
We are waiting for months to see this fixed.
For now, downgrading to 121.0.5600.50 seems to be the only option.
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Also mentioned in https://forums.opera.com/topic/86200/alt-enter-in-address-bar-no-longer-opens-a-new-tab
We are waiting for months to see this fixed.
For now, downgrading to 121.0.5600.50 seems to be the only option.
Still works like a charm for me. Before it did show a fraction of the advertisement before skipping it.
Not it doesn't show anything, only a pop-up once in a while informing me about the number of minutes it saved me. 
I am using Opera GX by the way. Apparently it doesn't work for everyone (which is strange), but I still think it is worth a try!
How long are these April Fool's shortcuts going to remain?
The Alt+Shift+M shortkey is hindering the one I use(d) a lot for a plug-in during development work and it is becoming extremely annoying.
I find it unbelievable how such a thing (messing with peoples personal settings/preferences) was even considered an option as a joke like this.
Actually works great for me on Opera GX, after the regular adblocker stopped working. That last one did seem to change by the time. YouTube (understandably) seems to try pushing its adds through though. It will probably remain an ungoing battle.
My usecase:
As a web-developer using Opera (GX), I would like to configure where my devtools would be located when working on a landscaped size browserwindow (e.g. right) or a portrait size window (e.g. bottom).
This way I don't have to manually change its location when moving my window from one (rotated) monitor to the other (not-rotated).
Firefox, and even Edge, has this feature as well.
I understand it is not groundbreaking, but it sounds too simple to not implement. Especially since it does not conflict any other features.