First, are you sure it's expected to go lower? 1.082 to 1.022 would be a little over 73% apparent attenuation. What were your grain bill, mash temp, mash length, and yeast strain?
I made this mistake with the london fog expecting brewfather to be accurate with the attenuation and it was way off. I adjusted the attenuation to the midpoint and it is exactly where im at. So I adjusted all the yeast strain attenuations and am looking for more predictable results.
The refractometer vs hydrometer question only really comes into play if the apparent attenuation is extremely low (under 50%). If this was a refractometer reading at 1.022 (5.5 brix) with an OG of 1.082, you'd be looking at a corrected FG around 0.988.