Electrical issue, possible charging issue, parasitic draw

In short, you sound correct.

This means we need to start with checking the battery and alternator to find out if the new battery is just going to do the same thing.

You could still have a draw and I will attach a diagram to show how to test for this.

Here are two guides that will show how to test for the battery and alternator issues. Most parts stores can do these free of charge.

https://www.2carpros.com/articles/car-battery-load-test

https://www.2carpros.com/articles/how-to-check-a-car-alternator

Once we confirm these are ok or you replace them, we need to check for a draw and just make sure that is not an issue as well.

Below you will see how to hook a meter up in series with the battery so that you can see what the current draw is with the engine off.

This should be low on this vehicle. Less than 35 milliamps (.035 amps).

Let's run through this and tell me what questions you have on this.

Thanks