Hello Federico!
Thank you for contacting The Elder Scrolls Online Support team!
Allow me to introduce myself! Ahem. My name is xxx (i'm not a a bad guy i won't burn the cs person that gave me this answer) and I am the most amazing Sorceress in all of the land and I'm here to help with my magic!! Well.. that's how it works in my head at least! No worries! You do not need to create another ticket.
Many of our players have been having issues where their enemies do not appear! Getting killed for no reason does not sound fun at all. However the fix for this issue is an easy one!
All you need to do is press play from the launcher and that should take you to your log in screen. Once you get to this screen, instead of logging in like you normally do, I advise that you please select the "Settings" tab on the left side of the screen. Please then click on "Audio" and turn down Master Volume down to 0.
This is the current work around for your enemies not showing up as they should! Please feel free to reply to this email if the steps above do not resolve your issue!