The sound comes from the left side only. I tested with another voice pro remote and showed the headphones do work correctly. I just received the remote the Ultra player. Everything else seems to be working fine. The reason I bought the player was to have private listening. Do I return everything I received, or just the remote?
I just saw in the Return/ Replace policy that when a defective device is part of a bundle, then the entire bundle must be returned for replacement.
You might try contacting support at https://support.roku.com/contactus and see if you can get to one of the chat options. No guarantees, but I've seen people here report that they managed to get Roku to send out a new remote.