I recently saw an issue with Windows 10 with latest updates where language bar was missing for one particular account. I checked all the standard things and all check boxes/options which may be necessary for it to be displayed are in place (example of things I checked).
Could it be something to do with the fact that this is Microsoft account and no local/non-microsoft account/profile was created first? This new user has been added from the very beginning using Microsoft account.
Any ideas what can be done/checked here? Just try to recreate user profile or am I missing some better solution?