Perhaps his joy is waning, he is speaking critically of fellow believers, or he has become secretive.
فَرُبَّمَا تُلَاحِظُ أَنَّ فَرَحَهُ يَتَنَاقَصُ ،‏ أَوْ أَنَّهُ يَنْتَقِدُ ٱلْإِخْوَةَ أَوْ يَصِيرُ كَتُومًا .‏