When using the language toggle on PointFire 365, for some users changing language takes about one second, while for others it can take several minutes.  Why?

The usual way to change SharePoint language is a long process ending with a message that says "Your changes have been saved, but they may take some time to take effect.  Don't worry if you don't see them right away."  After this it may take several minutes for the language change to take effect.

For PointFire on premise, the change is immediate.  That is because on premise PointFire interacts directly with the SharePoint server, something that is not possible with SharePoint Online.

For users having high enough permissions, if the language change is requested when the tenant's SharePoint Online servers and backend SQL Server databases are not busy, PointFire can change the language in a fraction of a second, then check that the language change was successful and then reload or redirect the page.  There is a lot of synchronization of settings going on in the background, with Active Directory, with the Office 365 User Profile at the tenant level, and with properties at the site collection level.  If your account has sufficient permissions, PointFire can force that synchronization to happen quickly.

However for users with lower permissions, they have to wait until SharePoint and Office 365 carry out the synchronization on their own schedule.  Language preference synchronization is a low-priority task for SharePoint Online.  The timer job typically runs once every minute, but often it misses its turn when the server is too busy, and goes back to the end of the queue.  If PointFire detects that user permissions are low or if language change is taking a long time, you will see a message that this may take a while.

Luckily, the users who most need to change their language back and forth are the users who have write access and the high permissions that allows PointFire to change the language quickly.  For other users, PointFire cannot speed up the language change without some compromise on security.

A future version of PointFire 365 will let you install PointFire with the ability to elevate the permissions of low-permission users in order to let them change their language quickly, if you believe that this security exception is a good compromise.