Incremental reflection update based on new files provides wrong results


I have a parquet dataset with an aggregation reflection. Every day new files are added into this parquet dataset, containing log data of the day.
I thought I could use the refresh method “Incremental update based on new files” for updating the reflection, however the result provided is wrong.
I execute the same query (a simple count(*)) when the reflection has been updated with refresh method “Full update” and i get a different result (440 over 887).

Any insight and know issues about refreshing with "“Incremental update based on new files” ?