Relatively fresh deployment of Matomo 3.9.1 - the email reports contain the IP address of the server instead of the hostname:
Please find below your day report for site
Site - Daily Digest
Date range: Tuesday, April 30, 2019
Sent from http://192.168.4.251/.
We have multiple servers running behind a load balancer in AWS and have set things such as trusted hostnames in the config.ini.php file. We've followed the steps in this guide to implement load balancing: https://matomo.org/faq/new-to-piwik/faq_134/
I've also tried updating the piwikUrl row in the database however it just gets updated by itself to the IP address of one of the servers.
Happy to provide other information, just let me know.
Is any of the trusted hostnames an IP? I'll create a comment in https://github.com/matomo-org/matomo/issues/11029
Thanks @tsteur - I've put a comment onto the other thread with some more information.