We recently purchased a used 2005 XC90 2.5T. One of the key features for us is the rear entertainment system (RES). We have a 4 year old. The wireless headphones that came with it, worked; but were a bit grimy. We decided to replace them. At first the replacement sets were intermittent, but eventually started working fine. Now, after about a month both the old and the new sets stop working properly. Only when I place a set of headphones within 6” of the right rear monitor will it work. I can’t get any set to work at all near the left rear monitor. I put in new batteries, maxed out the volume on the displays and maxed the volume on the headsets. Has anyone else experience this? Any good suggestions?