a lot of xtr brake in asia had a problem like this

may be this product can t be use in hot country?
this pic just some of us that have this problem
this happan to me as well. but less than above pic(but i need to used full finger glove and need to wax them with car wax every 2 week for stop cracking but they just slow down )
and in our country have 2 shimano dealer and dealer1.hard to claim
dealer2.very harddddddddd to claim .
most of us give up and very disappoint in xtr brake.
any one els in mtbr experience this issue? thx
from asian mtb