Mine has the same problem, I have a T-scorp like that, I tried spraying it with mite/bug spray a bunch of times, I tried a soapy pesticide, I tried vinigar/water solution that kind of damaged a few leaves a little more, and I even tried plucking off all the effected leaves and all the new leaves that come up, do well, until they get a little larger then they start to act weird.. I have just chalked it up to genetic defect.. like you it is the only plant like this out of about 100..
here is what it looked like about 2 weeks ago or so.. I plucked off all the effected leaves you can see in the pic and it still is there.. but it is growing, it was stunted pretty bad at first, but it seems that it is coming along better now.. just taking longer.. and I had it close to a bunch of other plants for a month or more and even now I have it near a few other plants that I have growing in party cups still, waiting till they get a little bigger before sticking them in the 1 gallon containers with the other ones.. nothing else has been effected/....
actually after just checking downstairs again, I noticed that one of the Jamaican hot chocolates I planted have been a little strange too, one of the leaves just started curling around kind of like a spiral, and itis pretty stunted now.. so I think I am just going to take them both out and stick them alone for now and see how they do, and just plant them completely alone when it gets warm enough out.. what a pain, I need to plant some extra Jamaican hot chocolates now.. only had 2 of them come up, and with this one possibly being infected.. I'm not leaving it up for just 1 lol
good luck
btw here is what the TS looked like a few weeks ago.. it looks mostly better now, but still kind of "messed up" the new leaves look good, but then they just end up like the older ones on here.. it sucks