It is trust accounting income (TAI) that is relevant. What are the terms of the trust? Are you. as trustee, required to distribute all income (TAI) currently?
Review your 1041 in Forms Mode, specifically, your TAI on the worksheet on that form. A rental property sold at a loss should not affect TAI.
Please note that tax scenarios where trusts/estates own (and dispose of) depreciable assets are somewhat complex. You might want to consult a legal and/or tax professional for guidance.
