Hi, just seen this. Hopefully you’ve figured it
out already but will give my advice anyway. Spray tanner of 7 years here. This is not exfoliated enough. Since your skin is this dry, that you are exfoliating and this is still happening, I would suggest using a tan eraser (google it), and exfoliating with that. Wash first and then exfoliate all over until you think you are done. Then do it just as thoroughly again. You should feel like your whole body has had a pedicure (you know that squeaky clean feeling after a callous has been scrubbed?). It is possible you may have eczema? Or another skin issue - as I have the old elephant skin on my upper arms and although the tan eraser (amazing thing!) got rid of it completely and I use it as soon as I get any new bumps, where it was I still get the odd few small white pinprick areas where it just doesn’t like to tan.
Never listen to anyone that says to moisturiser before a tan as it will never be true to colour. You may as well be bathing in oil for the good it will do haha. Never on the day or the day before and never after unless it’s oil free.
Another thing to consider is the shaving. You can actually do it super gently after tanning using some sbower gel but never the day before as the strips on the razor and shaving gel/foam all interfere with tans.
Hope this helps!