I am in the deck construction busines and when I see this situation, I wish that I had spoken with them prior to this application.
Actually PT wood will look like Redwood, cedar, and others when left alone. Meaning a fence looking gray. Some people want that, others want to preserve the appearance of the wood.
First, NEVER use a topical only protectant like yours has. You want a stain/procectant like CWF-UV or any products by the Wolman Company. These products soak in and create a stained look and do not chip and crack and alligator. What you have is something like a polyurethane finish.
Here is what I would recommend: Get a floor sander, barrel sander or drum sander and start with coarse paper then go to medium. Always and in the direction of the grain.
The deall with sanding Pt wood is not to when its wet. The burning of pt wood is the main no no. Otherwise, if your overly concerned, use a mask.
Now, when its sanded down all pretty, wash it off with only water. If its stained alittle use bleach and water. Then let it dry for a day or two.
Now, get either one of those products. you apply them with a brush. I have always subscribed to the practice, if you spray it on its not any good. You want to brush it on and brush it thick. The first application will soak in, but then after, you have your base built up. Do this every spring or every other.
DO NOT USE ANY PRODUCT BY THE THOMPSON'S COMPANY.
After this work and effort, you will be proud of your deck again.
Again, both of these products are intended for use as a stain and do soak into the wood. The coatings you have now on your deck MUST come off so the product can sink in. These do come in different colors, like clear, cedar, redwood, and others.
I use only these two on decks I build and have had good results. I do tell my customers that this is not for life and it has to be reapplied every year or every other at the most.