The simplest reason why the Trump administration is cutting off SNAP, despite adequate reserves, is that they hate the program and don't care about the people who depend upon it.
They are breaking the law not to provide SNAP while also enforcing the "equal treatment rules" to hurt SNAP users.
The USDA sent an email to grocery stores telling them they are prohibited from offering special discounts to customers affected by the SNAP funding lapse.
I'm aware of at least 2 stores that had offered struggling customers a discount, then withdrew it after receiving this email