.NET Core monitor is not showing data

Yesterday I installed the monitors for both .NET and .NET Core to the web server hosting most of our apps. The data returned is not what I expect:

Only one .NET app is listed in the APM Insight Overview page, despite there being traffic on multiple .NET apps.
No .NET Core apps appear anywhere that I can see.

It seems relevant that in the Edit APM INisght .NET Agent Configuration dialog, I see ALL apps listed on the Apps tab - .NET and .NET Core alike.

I've followed the troubleshooting steps here:

https://pitstop.manageengine.com/portal/en/kb/articles/dotnetagent-installed-but-no-data-available

but no dice.

I have both agents configured with "Use HTTPS=false" and the same hostname/port. Both agents and APM are all running on the same machine. I've been through an IISRESET and recycling application pools.

What can I look at next to get this working?