I just created a new Org with an app that is still reliant on the Classic interface. I can easily switch back to Classic with the admin user, but with a new Salesforce Platform user, I cannot even see the option in the Lightning interface. Obviously, the first user is an admin, and the second isn't - but what gives?
Of course, I checked the profile of that user. "Hide Option to Switch to Salesforce Classic" permission is not enabled. "Remain in Salesforce Classic" is enabled. "Lightning Experience User" is disabled.
And just to be sure I just enabled ALL "General User Permissions". I also enabled all of "Administrative Permissions", except for the two options mentioned above. Nothing works. What am I missing?