Esto es lo que pone en .eu :
Some facts about OTA delay:
OTA packages are always same as posted here, so FULL ROM (400-1000MB)
Installation via OTA is same as you do, so Updater - Menu - Select installation zip
OTA is uploading into Xiaomi china servers which are very slow for download and upload (usually 30-40kb/s for uploading over 10GB) so I have to upload them always at night one by one and I dont have time for doing that every week for 30 devices... Unfortunately OTA account is binded to my Xiaomi account so nobody else can do that instead of me...
So we decided to STOP OTA support at all.. you have to download ROM manually and install via Updater - menu (...) - Select installation package - reboot (You will not loose your data)