Don't worry. 無人怕羞得過我個女,even 見到D一個月見一次的親人佢都會哭到不停. 朋友來我家又哭不肯見人,每次去人地party 必哭即走所以有時唔帶佢去。this prb lasted till she was 3 yo, from then on, not too shy, won't cry and will answer questions from strangers.
my son was the same b4. Well,I think it's sort of personality. Can be improved but not big change. Find a happy learning kindergarten for him. It helps!