Duplicate id's in API search results

[symaonz]

Hello,

When running a query to get all unique id’s for an entity we see different results between NPE and LIVE environment.
Adding “sort=id” in the query gives a set of unique id’s in the NPE environment.

However, running the exact same query on the LIVE environment returns some duplicates on each run.
The number of duplicates and the id’s of these duplicates differ on each run of the query.
This happens for Candidate , Clientcontact and other entity types.

We use this this query in a loop with count=500

search/ClientContact?query=id:[* TO *]&fields=id&sort=id&showEditable=false

What could be causing this?

Kind regards