I think we have to keep a couple things in mind here:
1) There are strong pro-Hamas / anti-Israel elements in the Democratic Party, and surely some of those in the Biden Administration. Parts of the bureaucracy behind getting weapons sent may be getting seemingly subtle but actually significant hindrances and delays deliberately effected.
2) The Biden Administration proved utterly incompetent in getting weapons Ukraine needed for what was supposed to be its 2023 summer offensive to Ukraine on time. That was NOT a matter of lack of funding at the time, nor was it opposition anywhere in the Administration, so far as I can tell, to sending weapons we actually said we were going to send.
Either or both of these may be in play. I would guess both. Biden’s mixed messages and lack of real leadership surely do not help.