Connected banks and logout

Since Friday evening, I’ve had a problem with my John Lewis credit card repeatedly expiring its open banking connection within 5 minutes of reconnecting.

In-app chat have separately suggested both deleting the app and logging out, but I’m worried that either of those could lose my two years of data - things like transaction notes, and allocation to custom categories. Those things aren’t documented in the Monzo API so I suspect they’re only stored locally. Can anyone confirm?