Could I use the old $19 Apple TV remote with Apple TV 4K A1842

Apple Aluminum Remote - Apple which came with Model A1469 (Apple TV 3rd Generation - 2012) does not work with Apple TV HD (2015) Model A1625. However, the same remote works with model A1842 (Apple TV 4K - 1st Generation - 2017). Very interesting!

The compatibility listing on Identify your Apple TV remote - Apple Support say that Apple Remote (aluminum) should be able to be working with “any Apple TV”, including the A1625. Not sure why it doesn’t work for you.

Apple TV (3rd Gen) and older Remotes do not work with the 4K (Gen 1 or Gen 2) correctly.

The Older remote will not have the full functionality of the 4K TV Remote. You can use a programmable remote or the older remote with limited functionality.

What is the model of the old remote, or, you can post a photo? Identify your Apple TV model - Apple Support can also help you identify the corresponding remote.

Also, you can Set up the Apple TV Remote on your iPhone, iPad, or iPod touch - Apple Support.

You can use the older model Apple Remote (aluminum) with any model Apple TV. But it lacks some buttons that the newer remotes have (most notably the TV/Home button to access Control Center). Functions that rely on the extra buttons may be inaccessible with the older remote.

You can use the older model Apple Remote (aluminum) to help set up the software remote on your iPhone or iPad. That would give you a TV/Home button in a roundabout way.

The 4K Gen 1 ATV just blinks the front panel LED, but has not other reaction. Even HDMI-CEC to a TV does not work when this remote is used. I will experiment a bit.