Use this if your TV has no internet or the OTA update fails repeatedly.
If your TV cannot find the update automatically, you can perform a manual update using a USB drive. Latest Software Update for Xiaomi Mi Smart TV How to Update Software on XIAOMI Mi TV 4A 43
Sometimes, you know a newer version exists (perhaps from online forums or a friend’s TV), but your Mi TV says, "Your system is up to date." This is a common frustration. Here is how to bypass it: Use this if your TV has no internet
Here’s a clear, step-by-step guide you can use for a blog, support document, or manual: but your Mi TV says