Why is the Vault Query Language (VQL) query result limit lower than the default setting for some queries?
The reason the affected query is returning less than the default limit values is due to the number of fields that are being queried.
Per the help documentation, when performing queries with unusually large numbers of fields in the SELECT clause, the API may scale down the number of results per page to reduce stress on the memory limit of the system.
This is not something that can be adjusted as it is done for performance purposes.
Vault VQL Documentation: PAGESIZE/LIMIT Parameter