This article describes the reason why some of the config change records would not be visible/missing in "show system commit" output.
>show system commit 28 2024-01-17 21:44:24 PST by user via cli commit confirmed, rollback in 10mins 29 2024-01-17 06:21:09 PST by user via cli 30 2024-01-17 06:20:15 PST by user via cli >>>>>>>>>>>No commits visible from time 27/09/23 to 17/01/24 31 2023-09-27 05:22:30 PDT by user via cli 32 2023-09-27 05:22:13 PDT by user via cli commit confirmed, rollback in 10mins 33 2023-09-25 08:42:16 PDT by user via cli
The "show system commit" command will not show the changes made when the device was booted from the OAM volume. The changes made in the OAM volume are not committed to the Junos volume, so they will not be reflected in the output of the "show system commit" command.
If Junos boots from the alternate media (OAM volume) and configuration changes are made during this time, the changes will be stored in the OAM volume.
After rebooting the device and it comes up from the Junos volume, the configuration changes made in the OAM volume will not be visible in the "show system commit" command output.
The "show system commit" command only displays the configuration changes that were committed while the device was booted from the Junos volume.
The changes made in the OAM volume are not considered committed changes in the Junos volume.
https://supportportal.juniper.net/s/article/Difference-between-request-system-reboot-junos-and-request-system-recover-junos-volume