Hey Jason,

This is an easy solution, and one you can easily do yourself ! Since the product you used is acrylic/latex based, sand all your 4 X 4 posts down to bare with an orbital sander. If they're super rough/beat start with 60 grit, then 120 to finish/smooth out. Remember to always sand with the grain. For those harder to reach spots and sharp corners, pick up a Dremel multi max tool for $ 100 at your local hardware store.. This way you can be more sensitive in your garden vs the Godzilla approach most contractors sadly use.

You're smart to switch products, for horizontal exterior wood decks I would NEVER use any latex based solid color products, as this will result in failure every time in snowy climates. Semi trans oil only, or upgrade the deck to to one of the plethora of composite materials available now, no staining/sanding ever again...Enjoy the new deck !