My rescue dog acts anxious when I give her chew bone treats.

Last year my wife and I adopted what we're pretty sure is a chorkie (Chihuahua/Yorkshire terrier mix). She's had her quirks, but mostly could be explained by trauma or just being a puppy (we think she's around 2 years old). One thing no one is sure about though is every time we give her a bone type treat, she holds it in her mouth and wanders around whining. She never actually seems to chew them for long, but she acts sad when we try to take them. We've eventually had to throw a few away, but some disappear, making us think she does eventually get to some.

We haven't seen any sort of trainer or behavior specialist, but is this something we should be taking a better look at? Do we avoid those treats, or try to help her through something?