The Stable update OS4.0.0.3.XAACNXM has been officially released for Redmi K90 Max (codename is prague). Before updating, please make sure you have downloaded the exact ROM matching your Xiaomi phone/tablet. In Fastboot mode, you can check model code by typing fastboot getvar product in cmd/shell.
The firmware files posted here are all official Xiaomi MIUI or HyperOS ROM, xiaomiROM.com do not own and never modified those firmwares，you will always download the file from Xiaomi server.
You may interest in those contents: Redmi K90 Max ROM Topics Xiaomi Devices Index
Download Redmi k90 max (prague) China HyperOS OS4.0.0.3.XAACNXM Recovery ROM with Android 17.0. Firmware size is 8.9 GB.