In reply to DaveHK:
Have you tried clearing your 'user data' and/or cache?
I don't know how you'd do that on an iPhone, but if you're on Android go into settings, select 'Apps & notifications', select the OS App, then 'Storage'.
There it tells you how much storage the app is using on your phone - 'user data' is your login details, downloaded maps etc. Clear the cache, nothing to lose there. If you clear 'user data' as well you'll have to log in to the app again and it'll have binned any maps that you previously downloaded.
I don't think uninstalling/reinstalling the app would have cleared that stuff btw.