Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Hello Aldo A Meza,
Thank you for reaching out to the Microsoft Community! I truly appreciate you bringing your concern to us.
From your description, it seems you've already tried adjusting the language settings in the correct way as the Official Instructions, but the UI still doesn’t update. We do understand the inconvenience caused and we are very sorry about it.
I also found the same issue when I tried to reproduce it for testing. After change the Display language from My Account page.
It takes effect on the portal and some other apps but The Planner.
As Recommended wait for a while and try with different browser.
What I found in my search that changing display language for Microsoft 365 websites sometimes it may take 24 hours.
So please wait for changes to apply and let us know if any other of your colleagues are experiencing the same issue. Also if you encounter any further difficulties or if we’ve misunderstood your request, please don’t hesitate to let us know.
Apologies for the inconvenience again. Your patience and understanding are greatly appreciated. Hope you stay safe and healthy.
Warm regards,