User export not working, just partial list (7 records)

1. Brekeke Product Name and Version: SIP Server 3.5.30

2. Java version: 8, build 65

3. OS type and the version: Win 7 Pro

4. UA (phone), gateway or other hardware/software involved:

5. Your problem:
User export doesn't work. I'm getting just seven of my > 50 users.
Bug? It is recurrent in 3.5.2 and up

Are you using any special characters in user names?

Yes, one of them has a special character. That is actually the reason why I've tried to export the list: I can't delete the user, so I wanted a clean user list and then import deleting the invalid record.

What kind of characters is it?

Originally an "é", but on the screen there is a strange symbol.

If you use another web browser, can you export the list?

I've found the error:
At some point in the description of a user a pair of " " and this character made the display of the CSV file be truncated in Excel.
The whole list was there if I looked at the file using a text editor.
In the text editor I've deleted all characters and then I've reimported the list deleting all existing records. Now it is ok.

Very weird...