Can Bus Comm Issues?

2018 Tahoe, 5.3, 2WD
I recently bought this Tahoe, last owner said these symptoms happened all at once but got worse. They had the ground at the battery replaced that goes to engine and frame, but it did not resolve the issues.

Symptoms
Tahoe will crank and drive but mainly stays in limp mode but will go in and out, you will have no power to running fine, but this goes back and forth, and the door locks will go up and down constantly.

What I've currently checked.
Voltage at the OBDII from Pin 16 to 4 & 5 = 13V
Voltage from Pins 4 & 5 to High & Low Bus at idle is low, both sides of bus read 1.36V
When Cranked the High Bus is 2.83V and Low Bus is 2.11V

Additional information
When in Accessory Mode
The Park Indicator will go from highlighted to unhighlighted and in unison when the P goes unhighlighted the traction control or stabilitrak lights up. I also hear a constant clicking sound that's coming from above the brake pedal and unsure if it's coming from the BCM. I also noticed the High and Low Bus Voltage will vary slightly with this clicking noise High will vary from 2.78 to 2.83 and low from 2.11 to 2.16 (not sure if in that order but they vary).

What would be your recommended next steps? I'm wanting to check the voltage at the BCM, also saw a video of bad solder joints in the BCM. How can I narrow this down to the BCM? I do realize it could be a bad wire or ground issue still. I did try using a jumper cable from battery negative to engine and frame to see if this changed my Bus Voltage readings and it did not.

List of error codes below after clearing DTC's

Thanks
Wes

Error Codes
p0700-00
p062f-00
u0422-71
u0101-00
b000a-00
b3111-00
c0755-03
c0760-03
c0765-03
c0755-00
u0101-00
u0121-71
u0100-00
u0422-00
u0100-00
u0121-71