@fullcalendar/moment-timezone Not working properly with Yarn

[ABAschedules]

It is the same error message as fullcalendar/fullcalendar#4530

It works when I use npm install --save @fullcalendar/moment-timezone

but it doesnt work when I use yarn add @fullcalendar/moment-timezone

My project requires Yarn

Can you fix this in Yarn? (Not reproducible with code)

[Dylan Ferris]

I tried this example project and have no issue installing or building with yarn:

https://github.com/fullcalendar/fullcalendar-example-projects/tree/master/moment-timezone

Please post a runnable, stripped-down demonstration or steps to reproduce the error if there is a bug.