Hi… fly logs -a app-name should give you the most recent 100 entries, in principle.
(However, that will tend to be missing the same time slots the Grafana view lacks, since they’re based on the same persistent store, as I understand it.)
There is also typically a delay in log entries reaching the historical store. I.e., often, you can see them in the live NATS stream but not in the output of a freshly started fly logs invocation yet.
Overall, gaps are not really unusual in the retrospective (i.e., historical) log entries. The following thread has several reports from a few days ago:
https://community.fly.io/t/grafana-showing-no-data-for-all-our-apps/26490
It seems unlikely that the restart itself caused the gap that you saw, though. I tried a fly app restart on a test app here and it didn’t lose anything. (Although it did take a minute or so for the new boot to appear in fly logs --no-tail.)