Writing dialogue takes practice. Content is one thing, punctuation is another.
A lifetime of formulating reports and briefings did not prepare me for this aspect of fiction writing at all.
We are told that dialogue done well, particularly with the punctuation correct, is seamless and goes unnoticed by the reader. Too true. I do not have any idea how my favourite written dialogue passages are punctuated.
There is plenty of sage advice on how to write good, engaging and compelling dialogue; but it is near to useless if you have not got the punctuation under control!