Investigate ispyb issue

At ~17:00 ispyb went down for a minute. This caused hyperion to stop, which is probably expected. However, a subsequent Hyperion restart after ispyb was back up did not recover the system properly. A restart back to an old version did but it's unclear whether it was a difference in versions or just that it needed multiple restarts. Discussion is at https://diamondlightsource.slack.com/archives/C017UDM8R5W/p1769625287227619

## Acceptance Criteria
- We understand why a hyperion restart didn't fix the issue
- We fix the problem so that if the same thing happens in the future a single hyperion restart would have fixed it (or even better no restart would have been needed at all)