This does sound like a battery issue. So even though the battery is new, let's start with testing and proving the battery and alternator as still fine.
Any parts store should be able to do this free of charge. Here are guides that will talk about the type of testing that needs to be done:
Once we confirm that these are fine then we need to turn to a body control issue or even a bus related concern. This means we need to start with checking for codes and making sure the scan tool used will be able to pull communication or U codes.
Once we know if there are codes and the battery and alternator are fine, we can take the next steps, but we can go past this or assume they are fine and no codes.
The next thing we are going to address are body control module issue but more than likely this would not cause a derate in power. So based on all this, I suspect we have some info to go on based on the above test. Thanks
Wednesday, October 13th, 2021 AT 1:40 PM