Ask in the kernel thread - if the kernel removes the hotspot feature there are 3 possibilities: (1) that's a known feature, (2) it's a bug they should know about or (3) you did something wrong.
But as that's XDA, do search the thread to see whether anyone else has had this before posting about it. Those are the rules over there.
Otherwise the only fix I can suggest, not being an expert on that device, is to try a different kernel.