Okay, so it is a totally different racquet. Everyone is confirming with you to go with your original thought and reduce the tension.
Going from 18X20 to 16X19 makes a racquet less boardy. But others are trying to tell you that you didn't just change this one variable ...compare the specs you listed.
How are you liking your new racquet in terms of stiffness, swingweight, balance or position of the sweetspot? Having it more stiff, less plowthrough, more head light, or missing the sweetspot can make a racquet feel more boardy too. You could try playing around with some lead tape to see if that helps.