This is now resolved. Behaving as expected now. The embedded checkouts will be ready for the next version of Chrome as well now.
The issue is due to a change we made with how cookies work for the new Chrome changes, but existing cookies set on your browser are conflicting with it. To solve this temporarily please clear your cookies. We are working on a permanent fix right now.
Again, sorry for the inconvenience.
We are currently having a problem with login and sessions, we are aware of the issue and working on rolling out a fix as soon as we can. Sorry for any inconvenience.