Changes made to travel attributes within a referenced Network Dataset service are not reflected in the Portal for ArcGIS Utility Services (Routes and Directions).

Workaround

Recreate all the Network Analysis services in ArcGIS Enterprise (Steps 5 through 7 above):

• In the Portal >Organization > Settings, configure Utility Services for Directions and Routing.
• Under the options for 'Configure routing services', select 'A network dataset that I'd like to publish'. 
• Select the datastore item that was registered containing the Network Dataset. 

Note: This takes considerable time and is not ideal for a production system that hosts Network Analysis services that are subject to frequent changes.

Steps to Reproduce