Smart Buttons render then vanish in net core 3.1 razor component

[kyalc]

Working if the setting is button().render('body'), but if I try to render anywhere else I get Error: ZalgoPromise at new ZalgoPromise' in the console. 

This is not an MVC app, strictly .razor components in a new server side Blazor app.

Running on an Azure Web App, but have the same results debugging locally.