You have multiple Listen directive that point to the same interface. Remove all 'Listen' and 'Port' dircetives from cupsd.conf and manage them inside /etc/cups/cups.d/ports.conf.
So, in ports.conf should be:
Listen 631
Also remove 'Browsing On' and 'RunAsUser' directives. Browsing is managed trough /etc/cups/cups.d/browse.conf.
You have multiple Listen directive that point to the same interface. Remove all 'Listen' and 'Port' dircetives from cupsd.conf and manage them inside /etc/cups/ cups.d/ ports.conf.
So, in ports.conf should be:
Listen 631
Also remove 'Browsing On' and 'RunAsUser' directives. Browsing is managed trough /etc/cups/ cups.d/ browse. conf.