I'm active DPOA for my 91 year old mother. I was elected after my oldest brother swindled mom out of her property that my mom continues to live on. Brother won't allow me on property to attend to mom as her durable POA. He calls the police to have me removed for trespassing because he wants to be POA can he keep me off the property and from my POA duties?
If your Mom is competent the POA is not in effect. And having POA does not mean you have to physically care for her. You just handle her finances. Make sure her bills are paid. Medical, you make sure her wishes are carried out. Talk to the Doctors and make decisions on what you think Mom would want.
Your brother lived in your mother's home on your mother's property. That property has since been transferred, legitimately or otherwise, to your brother who is thereby the recognized legal owner of the property; and your mother is still living with him.
I can't guess what you mean by "elected" DPOA? By what process were you given DPOA for your mother? And what do you understand your DPOA duties to be?
Your profile mentions age-related decline but says no more than that about your mother's mental state. If there is no impairment, then it is up to your mother where she lives and she can always move. But if she has foolishly or naively transferred the real estate to your brother, it is up to your brother who enters the house.
If you are prevented from speaking to or seeing your mother at all, that is a form of abuse - she is being deprived of her relationship with you - and you can raise a concern with Adult Protective Services; you should find contact details online easily enough. But this is regardless of who has valid power of attorney.
Do you have any other concerns about your mother's wellbeing?