"Why does my 1041 not show a refund?"
I assume you are not referring to the program's "refund monitor" since that functionality was removed several years ago.
Beyond that, if you look at the tax payments section of the form (see screenshot below), you should see that if the trust did not make any tax payments (estimated tax payments, withholding, etc.), then there will be no refund whatsoever.
Further, if estimated tax payments were made but allocated to the beneficiaries, then there will likewise be no amount to be refunded to the trust.