07 4.8i Electrical Issues

[BrenDen2425]

Hi All,
I am experiencing weird Electrical issues when slowing down or being stopped and idling. The center display will turn off, and the passenger restraint fault, level system malfunction, and CEL light will come on saying that it lost communication. Once I accelerate and get the RPMs up the screen comes on and the lights go away. Thinking it was a battery issue, I tried replacing the battery and registering it, but that did not change the situation. The battery I replaced it was a 92ah AGM, and the vehicle reads that it has a 90ah which I cannot currently change. Can the difference in ah be causing this?
Any help is greatly appreciated. Thank you for your time.