Holy moly, should I list my blood type too. By the way I've been having the issue over 9 months. I have an iphone Xr. I called MCD about 3 times and apple 2 times and still no fix. It worked on my iphone 6S and about 4 months after I got the iphone Xr it started showing the initialization error/critical error.
It seems like we all either switched phones recently or had a logon issue than it occurred. A tech person from a chat I use said its a linking/initialization issue when our phone links up to the app. If anyone does try to delete the app, and does a backup then resets the phone like it was new phone again. . . . please let us all know if that works, that seems to be the last resort in trying a solution before we delete it al together!!