This seems very unlikely, however, there are a few scenarios where you could create a situation that would have this result.
Some questions:
Is this a brand new Bitcoin Core wallet that you just installed, or did you recover this wallet.dat from somewhere? If you had recovered this wallet.dat from somewhere, then this address might have been used from the same wallet.dat AFTER the backup was created. As such, when the backup was recovered, it is possible that the transaction was forgotten about.
Are you (or anyone else) using the same wallet.dat in multiple Bitcoin Core wallets? If you created a copy of this wallet.dat and ran a second instance of the Bitcoin Core wallet on some other computer (or some other session on the same computer), then the other instance of the wallet may have pulled this address from its pool already, and now this instance is jsut getting around to pulling the same address from the address pool in the wallet.dat.
What operating system are you using, and what version of that operating system? It is possible that the random number generator of the operating system that you are using is faulty (or compromised) and that it is not generating actual random numbers. As such, if someone else is using the same faulty (or compromised) operating system, then they could generate the same address.
Are you certain that you copied and pasted the correct address? Perhaps the copy failed, and you pasted a previous address that was still in your computer's clipboard. If the address actually received bitcoins yesterday, then they should be added to your balance now. Did the balance on the wallet increase?
Can you run:
in the console of your Bitcoin Core wallet? Does that address (and transaction ouput) show up there?