Lemmy 0.13.0 invalidated all authentication tokens meaning your current account will cause infinite spinners in lemmur. This has showed us that we should improve invalid auth handling, hence I have created a report for that: https://github.com/LemmurOrg/lemmur/issues/265
Hmm, maybe the Lemmur dev could work around the issue by embedding the ISRC root certs for older devices.
https://www.danieldent.com/blog/android-apps-lets-encrypt-dst-root-expiry/