Creating a new file on every stop/start is expected, but it’s probably not the root cause here - Zoom’s documented limit is way higher (150 files per live session), so “3+” segments shouldn’t hit it.
The more likely failure mode is that your third “start” is happening while the SDK still thinks recording isn’t fully Stopped, which can cause RECORDING_MISMATCH_STATE (7202) - make the button wait until the status callback is actually Stopped before allowing another start.
Another common gotcha is segment length: if some of those stop/start chunks are very short, Zoom can show “recording could not be generated because the recording time was too short” (so it looks like “no cloud file” and no completion event) - see this Video SDK thread.
Also note the webhook timing: the session.recording_completed event fires when the recording becomes available, so if processing is delayed you won’t receive it immediately even if the recording was captured.