Do-not-email tick box not working and usernames changed

Hello

I am developing a website for a client on a subdomain.

I utilised the Cimy User Manager to import/export over 600 users from the current site to the staging site.

I was very careful to leave the tick box blank for email new and existing users, because I did not want any users notified.

However after import, I notice that quite a number of usernames were not matched up to the correct records. And in addition, ALL users were emailed and told that their email addresses had changed, which was not true.

I have been fielding unsubscribe emails and complaints from my client’s customers all afternoon!

I was following the instructions in this article that said to tick the Create Users box. Was that correct? Or did I miss a step somewhere? https://www.wpbeginner.com/plugins/how-to-easily-import-and-export-wordpress-users/

Anne