All 3 devices are currently running Android 11.

• App Version 5 regularly crashes and loses subscription.
• Install Version 4.1 to get rid of the problems, however Android 11 will always auto-update the app to the latest version.
• To avoid this
  1. download the Version 4.1 app with modified signature
  2. uninstall the official app
  3. install the downloaded Version 4.1
  4. alternatively, send the apk to yourself via email or messenger, and download and install directly on the phone or tablet
  5. or, try to modify the apk directly on the phone as described in Permanently Stop Any App from Updating on the Play Store — No Computer Needed