I had an interesting experience with a new Apple remote that I purchased specifically for my Pulse ∞
After successfully pairing, all buttons would only turn the volume down.
It wasn't until I power-cycled the Pulse that the remote began to work correctly
Unfortunately, this did not last for my Pulse Infinity. It went back to its original behavior. I also have a Pulse currently next to it and I paired the remote with it as well. It works fine. I opened a ticket.
I opened a support ticket and was advised to update the MCU firmware and that resolved the problem! I am now running v1.26