Email activity notification: problem with special character

I think there's a problem with at least one special character in the activity emails, more specifically in the user name for the anonymous upload user remote user.

Steps to reproduce

Make sure activity notifications via email are enabled for files/folders that were uploaded, created

Create a folder for public uploads and share it with these settings: shared by link, allow editing, hide file list, password protected
Log out and upload some file(s) to that folder
Wait for the email with the activity notification

Expected behaviour

Normal plain text email with no odd characters.

Actual behaviour

Email features " around the user name instead of "

Example message:
"remote user" created Uploads/somepic.jpg

Server configuration

Operating system: CENTOS6
Web server: APACHE
Database: SQL
PHP version: 5.6.21
Nextcloud version: 9.0.53
Updated from an older Nextcloud/ownCloud or fresh install: fresh install with old config.php and previous SQL database
Where did you install Nextcloud from: tar archive from nextcloud.com
Are you using encryption: no

Remarks

I think I have set UTF-8 for php etc., it shouldn't be that.