well, if the substrate is feeling dry, then maybe the wick system is no longer working as well as you think, eh?
either it can't keep up with the drinking or it is no longer wicking as effectively as before. in either case the rate of provision is not keeping up with rate of use. the plant is probably trying to drink as much as it usually does.
this assumes you have a good grasp of controlling ph and concentration levels of nutes. the problem with bottom feed is you don't get any runoff.. so potential for buildup of nutes is real and something to consider. in this case the plant doesn't look overdosed from afar. certainly not in a severe enough way to impact it's drinking.
is it still ripening? again, the picture is too far away. if it's 'done' it'll drink less as it nears death. kinda looks like it has time but too far awaay to see.