Dunno what could be causing it.
I put an RK on at 21,000. I'm at 38,000 now and it's doing fine.
They do need some adjusting fairly often until they set in, and then still need some, but not as often.
Do you have any tight spots?
Put it on a jack if you can, and rotate it slowly while checking the tension.
Might be normal, inspect it link by link if you have to.
