Steps to reproduce the issue

1. Upgrade a site to a higher plan in Calypso
2. Click start exploring your features
3. wp-admin appears with overlay - close overlap
4. Use a link to visit an external page - eg. WordPress.com stats
5. Use back button to return to wp-admin

What I expected

Overlay to not appear again as I've already dismissed it

What happened instead

Overlay appears again. Closing it creates a red error. See sceen recording attached.

Versions

Tested 5.7.1 and 5.8 in Firefox and Chrome

Screen recording