I stumbled across this post while looking for something else. I know the last response was a number of month ago be we had a very similar problem to this in oemr 7. I hope the OP has solved their problem by now but if anyone else encounters this, this might help.
@Jose_Jabe we had a situation where the vitals would show up on some patients but not on others after we upgraded from v5 to v7.
In our case the problem was that some of the old vitals records in the database contained 3 digits for the persons height. It looked like simple typos like 60in was entered in as 660 or 600. We had to manually go into the database and change the height records for these patients then the vitals started showing up.