It could either be adjusting to the conditions of your office/house, or it could just be the natural dying off of leaves that occurs in all plants. Old leaves die and are replaced with new ones. I wouldn't worry unless the trend continued up and the palm showed signs of browning on all leaves. The picture shows dark, healthy younger fronds so I don't think you have a problem.

When a palm leaf becomes damaged/disfigured, etc., it doesn't recover no matter what you do. You can only watch for changes in new leaves. But as mentioned, your palm leaves are probably just going through senescence (old age). As long as new ones are replacing them there's no problem.