Mozilla VPN promotional banner still displayed after closing it

[Bianca-O]

Build:
Stage

Affected platforms:
Windows 10 64-bit
macOS 10.14
Android 11
iOS 14.6

Browsers tested on:
Firefox

Steps to reproduce:

1. Launch Firefox with a new profile.
2. Navigate to https://stage.fxprivaterelay.nonprod.cloudops.mozgcp.net and log in using an existing account.
3. Close the Mozilla VPN promotion banner.
4. Click FAQ.
5. Observe that Mozilla VPN promotion banner is still displayed.

Actual result:
Mozilla VPN promotion banner is still displayed on FAQ page after closing it on Home page.

Expected result:
Mozilla VPN promotion banner is not displayed anymore after closing it.

Note:
If the user is logged out and the promotional banner is closed on Home page it is not displayed anymore on FAQ page.

[maxxcrawford]

I took it a step further – if a user dismisses it on home/FAQ and THEN logs in, the banner stays hidden. It's only when they dismiss from the signed-in dashboard. Weird.

I experimented with adding secure; and SameSite=None attributes but no dice.