[Bug][Calendar] Calendar body disappears in StrictMode

[filipKovachev]

I'm submitting a...

• Regression report

Current behavior

When rendering the Calendar component in StrictMode and next to a Grid, the body of the Calendar is missing. This behavior is observed in version 8.1.0 of the components and above. In version 8.0.0 the Calendar is rendered as expected:

https://stackblitz.com/edit/react-mec2dy-v45w4q?file=package.json

Expected behavior

When the Calendar is rendered in StrictMode and next to a Grid, its body should be rendered.

Minimal reproduction of the problem with instructions

1. Open this example with version 8.1.0 of the components and observe the missing body: https://stackblitz.com/edit/react-mec2dy-qq5l5a?file=app%2Fapp.tsx
2. Remove either StrictMode or the Grid definition and observe that the body of the Calendar is now visible.

Workaround

https://stackblitz.com/edit/react-mec2dy-9cp97e?file=app%2Fapp.tsx

Reported in Ticket ID: 1658012

[iadnonov]

Fixed in dev version v8.3.0-develop.11