A device can support 4K output while a specific stream is only available at a lower resolution.
Step 1: prepare
Write down the device, player version, connection and what you want to measure for HD and 4K streaming. A device can support 4K output while a specific stream is only available at a lower resolution.
Step 2: run the check
Compare the stream label, TV input mode and available bandwidth. Test a second example and make one controlled change at a time so you can tell what made a difference.
Step 3: decide
Record the result, full price and support response. Treating a marketing 8K name as proof every programme is delivered in 8K. Repeat the test if the comparison was made on a different network or time of day.
What to do next
Open the relevant brand page and check the original supplier information before ordering. For a technical issue, write down the device, player, connection and one reproducible example. For a price question, ask for the full charge in the currency you will pay.