Vehicle Speed Control Related Problems of the 2016 Mercedes Benz Metris

Vehicle Speed Control problem

Engine on and vehicle parked for 10 minutes with parking brake applied. Leaving from a parked position with engine running, parking brake released, I shifted from park into drive but the vehicle showed I was still in park. Could hear transmission shifting from p to d and to r but no information feedback. Eventually I found that I could engage in reverse, neutral, park, and drive but only park was showing on display. I tried restarting the van but it didn't change. Received errors for turning car off while in drive even though I was in park. I ended up driving with the car in "park" for about 100 miles to my destination. During the drive, there were lots of errors mainly the speedometer would not work ( had power but only said 0 mph). The tachometer remained at ~800rpm regardless of actual rpm. The gas gauge wouldn't work. Numerous errors occurred with the active braking system (alarm only). The srs defective indicator remained on the entire drive. When I reached my destination (gas station), shifted to park. I turned the car off again and completely disconnected everything electrical and let the van sit for ~5 minutes. The errors cleared when I restarted and the speedometer/tachometer/gas/srs all worked but I had a new check engine light activated. The only message was still related to srs but the cel stayed on even after acknowledging the service message. After about ~200 miles and 3-4 restarts the cel cleared and everything worked properly for the remainder of our trip (about 1000 miles round trip). Later, I was able to recreate a similar system malfunction when applying the parking brake. I've since been able to conjur random errors all related with safety systems and the park/drive/reverse scenario 50% of the time after applying and releasing the parking brake. The errors only happen after activation and release of the parking brake (so far to this day).