too quiet to be honest

“What’s the matter with my boy, he is too quiet to be honest.”
What is the meaning for ‘too quiet to be honest’?

It would be easier to understand with a comma:
He is too quiet, to be honest.

‘To be honest’ does not refer to the boy, but the answer.

I tell you honestly, he is too quiet.

His this statement grammartically correct’‘i am completely with you,all odd reactions are basically to guide me’’

I don’t think it is as I can’t understand what it means.