Seems like BMW may have "updated" how this process works with phone integration. I distinctly remember a section in the old app that allowed you to check for updates and then download the update directly to your phone (either via WiFi or cell data). Then later transfer the update from your phone to the car. Once uploaded to the car, you then had the option for when you wanted to install the update. FWIW, I went looking for the "Update" option in the old app and could not find it now - removed by BMW in preps for the new app
: ??
My drive to work is barely 5 min and the upload process (or preparing process that the car tells you) from the phone to the car took less than 10 min (two separate trips for me) for the upload to complete AFTER I successfully downloaded the update to my phone at home on WiFi with the old app. So I will speculate that BMW may have attempted to make this process more seemless with less interaction from the vehicle owner - but it does not appear to be working out that way, at least for some.
I am on a road trip now and have been checking periodically for this new update but have not seen it yet - in the X7 or on my phone. But the idea of needing to log out and log back in again for these "new" process changes to take effect does not surprise me….