If you see a disparity between trichome development at top and slightly below (more below), then you might be evaporating it. it's poissible that it is genetics as to why one is less sticky than the other or possibly a late bloomer etc.. many possibilities.
I wouldn't worry... just keep eye for bad signs, but if healthy and it's got good genes, it'll be fine in the end.
side note based on pics in diary -- becareful of cotton shirts or anything that can shed threads near sticky plants. You'll end up with little strings in your buds as they develop and a nice surprise for you to find later... preferably not by horrendous taste. It only takes a glance and it'll be like velcro to cotton and other similar materials. Same with harvest. It seems silly, but you want to cover yourself up with plastic or similar.