Are main residence taxes and interest deductible when I am also renting out my previous residence and deducting prop taxes on that?

My previous residence is now being rented out.  I lived in that house for the last 60 years.  That residence is paid off.  I've been told that I cannot deduct my new home's mortgage interest nor property taxes because of me having that rental property.  I guess I should also note that the rental property is located on my farm land.  I still operate the farm land.  The home on the farm land is rented out to tenants.  They only rent the home.  My new residence is completely separate from the farm land.  Why am I being told that my main residence interest and taxes cannot be deducted??