Can't access Curriculum without being signed out

1 - If I’m Signed in AND at the Greeting page, when I click “Curriculum” button, it leads me to the the current lesson’s page but as if I’m signed out;
2 - Then I click the “Curriculum” button from the Greeting page and I’m led to the Curriculum page but as if I’m signed out so I can’t see my progress.
Evidence (Reproduction):
Using Firefox v61.0.1 (64-bit)
SO: Windows 10 Pro 64-bit

I have this same problem, but a different version of Windows.

I signed out and signed back in. That fixed it for me.