This isn't the first system bug that primarily was visible due to headspace: https://www.macrumors.com/2017/12/02/ios-11-1-2-date-bug-cra...

In 2017 it was an endless crash loop caused by any app with local time-based notifications.... Which for almost everyone at the Apple store I visited was meditation apps with daily meditation reminders (in Australia we were among the first to wake up on that affected date. The fix went out before most of the remaining world woke up)

I wonder if the daily reminder is triggering a reinstall? Perhaps try disabling the reminders before uninstalling.