only 1567 items are exported

You could using phpmyadmin export your “wp_users” table (or <table-prefix>-users), then you might be able to find where the other 233 users are hiding.

Export both as CSV, load each into different tabs on a spreadsheet, sort and compare somehow.

Thanks,
I understand that there is a php way to export,
but I am not familiar with php
will try to find someone to do it
or is there an easy way?

Sorry, seems that we have a difficulty with terminology.
Many / most web hosting environments have a database support tool called phpmyadmin, probably called this because it is written in PHP, but otherwise is just a GUI web program.
The easy way is to install it or use it to do an export and so on.

thank you for the answer
I will try phpmyadmin
but the problem seems to be related to the fact that we have imported new users via a routine that did leave some fields (such as name,nick name,..) empty and therefore export probably did not take them into account.
We will fix this bug and then see if export is correct