"we have offered detailed solutions [..] – but have received no substantive feedback"
And you most likely won't now.
Trump has spent his entire presidency avoiding actually answering questions - or making important decisions. The few decisions that he has actually taken were mostly terrible, and he's avoided answering for that as well.
Unfortunately for him, he will be held responsible for them, because he is.
Trump knows very well that anything he does now can and likely will be overturned come January. He's never been a hard worker, why start now ?