TreasuryDirect review: Account closure

I am the estate administrator for my late sister who passed away in January of 2025. I filed paperwork to liquidate her account so I can settle her estate. This was received by them in March, 2025. As of February, 2026, they have not processed the request. I would like to file the estate tax this year without having to ask for an extension. I was told they process them in the order they receive them. What's the hold-up?
I have called them numerous times but nobody has any idea when this will be completed.