In WT-7929, we improved our stats gathering during the checkpoint. But it seems it is not working all the times. One example is in HELP-54566. The checkpoint runs for 30+ minutes and we are missing FTDC data during the time.

Investigate why we still have data missing during the checkpoint. Note that this may be a server issue as there was no server stats at the time as well. If that's the case, create a server ticket for further investigation.