Anyone else having problems with IRS processing delays for a timely filed form 1041-T to allocated trust estimated tax payments to the beneficiaries SSN?

We're having numerous discussions with IRS and puzzled by the long hold-up. In the meantime, the beneficiaries are receiving CP23 notices for underpayment, when in reality, they are due refunds.

Ironic that the IRS picks up the income from K-1, but not line 13A tax payments. We've even submitted EFTPS receipts, sigh.

In the future, should we just have the beneficiaries make tax payments themselves?