I interact with "Christians" on a daily basis. Many of them don't smile. Many are dour and sour. Most are
NOT apostolics.
Nowhere does scripture say people have to go around with a smile on their face all day long. Some people are naturally happy, cheerful, bubbly and smiley. Others are more serious.
Do you think Jesus and the apostles went around smiling and being cheerful always? I don't.