Inserting a team calendars macro on a page results in an infinite spinner

Issue Summary

Team calendars macro is broken. Inserting the macro results in an infinite spinner.

Environment

Fabric editor

All environments

Steps to Reproduce

1. Create a page with the new fabric editor
2. Add a Team Calendars Macro

Expected Results

A popup appears:

and the user is able to insert a calendar, and interact with it meaningfully (add new events, view events etc).

Actual Results

A different popup for configuring the macro is rendered:

On view, an infinite spinner is rendered. Sometimes it does seem to finally render something, but it's always an empty calendar with no option to add new events or interact with it meaningfully.

No relevant errors found in the console

Notes

The popup that appears in the legacy editor when adding a new calendar is quite different to most macros. It's not a standard "edit macro" modal provided by the macro browser.

Workaround

Use legacy pages instead of new fabric pages.