Hi @Seasalt, seems like the app only shows up in the “Choose an app to auto-start” list if it has the right scopes (for example a meeting transcript scope like meeting:read:meeting_transcript) and RTMS is fully enabled on your account.
If those scopes are set and the app used to appear but suddenly disappeared, that usually matches the behavior in this RTMS entitlement thread where the RTMS license on the tenant was removed or misconfigured.
At this point the next step is to contact Zoom via the RTMS access form or open a Developer Support ticket with your account ID and app ID so they can re-enable RTMS for your org and get the app back in the auto-start dropdown.