I asked this question at daz when I was wondering why my hair went all "bendy" at a certain point. On one render, it turned out to be the eyelash lengh, but I think something else because it stayed a little bent, but I could live with the render at that point. However, i have noticed it happening a lot, and wondering what else I can check. One of the renders looks like this(see by her eyes how the strand has a sharp angle? and the second has a bend in her right ponytail?)

It looks like the hair as you said is being effected by a specific morph without the aid of a corrective morph. If you can locate the morph on the figure which is the source of the issue. You can turn Auto Follow off for that morph by using the gear icon on the morph and unchecking Auto Follow.

Auto follow is what reshapes the attached item to fit any morph adjustments to your figure, in some cases they are left on when they should be turned off. The worst cases are with things like elf ears which drastically stretch hair.

Or alternatively show hidden morphs on the hair and check the corrective morphs that have followed on from the figure and dial it out to 0%.

Ah, I was showing the hidden morphs but there are so many corrected, that sometimes I can't find which one is the culprit. I didn't know about auto follow. I will have to check that out. Sounds way easier. Thanks! Hopefully that will do the trick. I'm tearing my hair out..lol..

I usually see that when I use autofit on a hair model. Could that be what you’re doing? If so, then scale and position the hair on the model without using autofit, and then parent it to the head.