The device and platform
Similar names can hide a different device
Xiaomi’s original Mi TV Stick page identifies Android TV 9.0 and describes casting in 1080p. A later product carrying 4K in its name is a separate model. The word Stick and a familiar remote shape are not sufficient evidence that the devices have the same output or software baseline.
Read the model information on the unit and its installed software. Retain the full name when asking a question. A response intended for a TV Stick 4K should not silently be applied to the earlier Mi TV Stick.
Separate a hardware limit from a soft picture
If the actual product is the earlier model, changing an account or buying a differently labelled subscription cannot establish a new hardware output capability. At the same time, a soft image within a supported output can have other explanations, including the selected source and its encoding.
First identify which question is being asked: what can the device output, what source is being played, or why does a particular picture look poor? Keep those facts in separate notes. A display reporting its own panel resolution does not answer all three.
Use the real TV app listing
For installation, use the application’s actual television-compatible distribution and current minimum requirements. An old Android TV baseline does not guarantee that every new player release supports the hardware indefinitely. The developer’s current listing matters.
If an app is absent or its requirement has changed, document that finding. Reinstalling an unrelated phone package or copying a code from another generation does not establish support. Any decision to use an external replacement should start from the application and output features you actually need.
Questions answered
Does every Xiaomi streaming stick have the same resolution?
No. Keep the specification attached to the exact model.
Can a new subscription change the device’s physical output capability?
A subscription does not establish a hardware feature that the device lacks.
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.