Interesting topic. It got derailed, but it’s still an interesting topic.
The term “universe from nothing” is true. It is also misleading.
The underlying cause(s) that gave rise to our universe were there before our universe came into existence, and they are still there (otherwise our universe would cease to exist).
The thing is, the underlying causes are not our universe, at least not as we understand it. They are something so alien and tenuous as to still have the power to be referred to as “mysterious”.
Space itself is one mysterious aspect of our universe. The universe as we understand it could not exist without it, whatever it is.
Matter is bubbling into existence in space as space continues to expand. This too is wholly mysterious at the present time.
Where things get confusing is in the language. Yes, there is something out there and all around us that has some causal relationship to our universe, but that something is something other. It is not of our universe. It’s all around us. It is connected to our universe. It is the underlying cause, of which we are the effect. But it is not us. It is other, with laws and properties that just plain don’t work the same as in our neck of the woods.
Let’s say that our universe is the foam you get from aerating water, and that aerated foam-water existed only here. THAT is the type of thing scientists are referring to when they say “something from nothing”. The sentient foam-water (us) doesn’t realise that it doesn’t really exist, that it is the temporary byproduct of turbulence. The foam-creatures living in the foam have their own little universe-within-a-universe, but that universe is not simply the air or the water. It is a made thing, from combining the two, and as it is neither air nor water, but the combination of the two under special circumstances, it is therefore a condition rather than a thing, and that condition, which is us, is something other in terms of water and air.