"Network topology must be enabled" error running Validate Network Topology in Python but topology already enabled

[KyleGallagher16]

We have a Python script that executes the following tasks on a UN Default version in sequence:

• Validate Network Topology (in sections)
• Update isConnected
• Update Subnetworks

Recently we encountered "Error 001793: Network topology must be enabled" when trying to execute Validate Network Topology through the script.

However, network topology is already enabled and has been for months per the Network Properties window in Pro:

We hopped into Pro and successfully ran VNT on the full extent with the ribbon tool. Hopping back to the Python script, we successfully ran Update isConnected, but it errored out again on Update Subnetworks with the same "Network topology must be enabled" error.

This appears to be related to this post although it is from 6 years ago using Pro 2.3. We have a UN version 6 and using Pro 3.1.

https://community.esri.com/t5/arcgis-utility-network-questions/quot-network-topology-must-be-enabled...

Thank you! 

[Brian_McLeer]

Does the geoprocessing tool use a database connection or the published UN service? In the past, I had to stop all published UN services to avoid a lock and use the DB connection with admin credentials. 

[KyleGallagher16]

Published UN service. We plan on running these tools against the services only.

[gis_KIWI4]

@Kyle - We haven't noticed this behavior with our UN. 
In the first screenshot I can see it's reaching section 6 before the error. Does that mean Sections 1 to 5 ran fine? 

It's hard to tell what might be causing it.

Would you open to sharing the code? Perhaps something lies within?