My mother was diagnosed with AZ about 5 years ago. She lives in her own home but my brother moved in about 1.5 years ago and he serves as the primary caregiver. I live in another state. Earlier this year, her primary care physician admitted her to the hospital for about 2 weeks for the leg sores. Once she was released, we asked that she be sent to a nursing facility because Mom had previously refused to allow us to care for her sores. She stayed in the nursing facility about 3 weeks until the sores were almost entirely healed. Currently, a wound care nurse comes to the house once a week to change Mom's dressing. My brother and I have been shown how to change the dressing the other days. My Mom sometimes argues with the nurse, but almost always argues with me or my brother, sometimes refusing to let us change the dressing or reapply it if she's taken it off. Also, she is often argumentative re attending doctor appointments, changing her wound dressings, taking her blood pressure and Eliquis medications, etc. I'm hoping others have encountered similar issues and might have suggestions for resolving them.
This is not saying your brother is not doing a good job but it sounds like mom is more cooperative with facility staff. Maybe because some "older people" tend to follow directions better if it comes from a "professional".
In the meantime , a dementia antistrip suit may prevent her from removing her dressings . Perhaps a med is needed to calm her down as well .