Need help with Douglas Fir deck!

We built a deck in March 2018 out of Douglas fir (2 by 6 boards I believe). I believe we let the Wood age a few months, then sanded with a floor sander, then cleaned with deck cleaner, allowed it to dry, then used Olympic Elite Kona Brown Woodland Oil. Over the course of one year the deck started chipping and we were getting splinters, and the color became very dull. So in Spring of 2020, we repeated the process. We sanded, used deck cleaner, let it dry for a few days, then used the same woodland oil. One year later it is again dry, splintering, and is just so dull and not very good looking.

Since being on this forum I have learned that sanding it was probably a bad decision because it closes the pores and doesn’t allow the oil to seep in, and if you must sand then you should wait a few months before treating the wood. Is this correct?

We have decided that we don’t like the color or the woodland oil at all. We want to use Behr Premium Cedar Naturaltone Semi-Transparent Waterproofing Exterior Wood Stain and Sealer on the deck, but we want to make sure it is compatible with what we have already treated the deck with and will stick, and also that the color will look nice. We are open to suggestions for other products to use, of course. We would like to know what we should do from here to get the color lighter while still being able to see some wood grain, if possible. We want our deck to look nice and lustrous and not dry and dull. Please help so we don’t keep making novice mistakes!
The first photo is from when the deck was new and wood untreated. Second photo is from last week.

Thank you!!