My 36's are stictiony when they've been sitting for a while, but fine in use once they've been moved (compressed) for the first time. TBH, it feels like the bushings are just a little too snug - which is probably better than the bushes being too loose but still not ideal. Side note - the same lowers have had two CSU's and felt identical (no issues with creaking, I just wanted black stanchions on my Waltly - not Kashima so swapped CSU's). I thought they had an issue similar to yours at one point, but it turned out the lower headset bearing was just starting to develop some play - bearing didn't feel too bad in the hand but it felt rattly through the bars (yes, I tried tightening the headset, made sure the stem cap wasn't bottomed out, etc... It was the bearing).
It was (is?) common that Fox 36's come with way too much grease in the lowers and choke the transfer port on the air-spring. That shouldn't make it knock though - just had to engage and harsh... If it's not brake knock like previously inspected - I'd be sending it away for inspection (given it's new).