My brother lives with my father. He hardly ever talks to me and the only time I hear from him is when he wants something. I'm my father's POA and I can't go over to the house because of my brother. He has a dog that isn't good around people and his boyfriend will not let me enter the house. My father refuses to get involved. I'm at my wits end. My father is 85 with health issues and I don't want to upset him but things are just getting worse.
If you continue to have serious concerns about your father's wellbeing - e.g. possible neglect of his health care needs, social isolation, coercive control, undue financial influence etc etc etc - then report your concerns to APS. You should do this, to place matters on record; only be aware that if your father won't assist you in intervening it's unlikely he'll co-operate with APS either.
When did you last have actual eyes on your father?
https://www.agingcare.com/questions/how-can-i-stop-my-brother-from-trying-to-take-over-care-of-my-father-466948.htm
What are your father's health issues? Are you able to take him to doctor appointments and/or follow up with his physicians to keep up on his status? Your brother can't really impede on your right in doing so.
And there are ways around his unfriendly dog - he can be placed on a leash when you're there - or is there a yard? And your brother's boyfriend certainly doesn't have a right to refuse your entrance into your father's house - does he also live there? That very questionable behavior on his part. If you're not able to gain access to see your father, ask them if they'd prefer your calling the authorities to join you for a wellness check.
As your father's POA, you have the authority and you need to be tough and direct and not back down to your brother and his boyfriend - regarding entering his house - and oversee his care - if you're not getting anywhere, you may want to consult with an eldercare lawyer in your area - even an initial phone conversation - so you can be informed of next steps in how to proceed.
Wishing you much success in this - it's time to really toughen up with them and steps in taking charge.
I WOULD however resign as POA by letter, and would suggest that brother, who lives with Dad, take on that duty. He is the one currently living with and seeing your Dad on a daily basis.
There is very little you can do about other people. If your father has no dementia then that's the end of this; it's his decision.
If he DOES have dementia severe enough to be incompetent in his own safety issues and care placement, and you are POA, then you may need to go for guardianship, removal of Dad from the premises and move into care. That would quite honestly be more of a mess than I would take on were it me.