It takes 5 to 7 seconds for the whole car to "boot up", which it should be allowed to do completely. [...]Rushing the car while it boots up and before it's complete can cause the wonky shifting.
Good to hear: this happened to me once as well and I thought I hallucinated it, except for the scratch on the garage door... I park on a slope near the garage door... I can't swear I did not fudge the brake/ON sequence by going too fast, but the car DID let me put it in reverse and would only go forward. It did that 3 times, and eventually I ran out of room and kissed the garage door with the front licence plate holder...which stopped the car... I killed it, got out to make sure there was no damage, got back in, cycled power on and this time all was well...
*IF* it was me messing up the brake/ON and the car lets you put it in reverse without power being on, that's a pretty glaring bug /stupid feature on VW's part... That would be like being able to pull a gasoline car out of PARK without the engine running. You shouldn't be able to...
I could pull my 6 speed manual Passat TDI out of Park on the handbrake/parking brake with or without the engine running, or the ignition on. Maybe turn the parking brake off last, after you put it in gear, with your foot on the brake pedal hard. That's normal operating procedure for me, regardless of which car I am in.
There's a lot of computerized booting up stuff going on on these newer technology cars. I find that if I turn the car on, then go to fasten my seat belt, then check all the gauges on the dash to be sure nothing unusual is lit up, that the system has plenty of time to boot up, and then put in gear and turn off the electronic hand brake. Establish a routine that works best for you, so time isn't wasted booting up, you are doing something productive with it.
The infotainment center will tell you when everything is pretty much up and running.