Using Microsoft Lists VS using Microsoft Dataverse in a Power App

I had to step away from a proof of concept I was working on.  Now that I have returned, I have some concerns and puzzles.

I thought I had created a Microsoft List from scratch for this proof of concept to be used by a Microsoft Power App.  But after looking closely at the Power App, I am not so sure of what is going on.  Maybe you can tell me what is going on.

I have created a Microsoft List and I created a Power App to interact with it.  Here is the header of the Power App loaded in the Power Studio:

The App is full of data and when tested seems to run properly.  When I investigate what its database connection is, I see this icon on the left side:

I am shocked that clicking on this icon does not reveal what I expect it to show.  I expect it to show that I am using a Microsoft List as a database source.  Instead, I see this:

This is not as I expected.  I notice that the name of the database is "x300 Proof of Concepts" whilst I remember creating my Microsoft List as "x300 Proof of Concept" (without the s at the end).  And when I bring up my Microsoft Lists I see the List that I expect to find.

While the Microsoft List "x300 Proof of Concept" looks similar.  I do not think it is exactly the same thing.  How can I find the other database and how can I assign my Microsoft Power App to the other data soucr, the Microsoft List?