Time zone keeps changing wildly
Just did a quick search on the Issue Tracker - you might want to follow these threads and/or contribute a bug report for them:


https://issuetracker.google.com/issues/120241605 Android Pie - Clock shows wrong time (intermittent)
https://issuetracker.google.com/issues/119663595  Automatic Time Zone Selection is wrong Android 9 Pie (has been closed because could not be replicated apparently)


Unfortunately yes you'll have to disable auto time zone for now.