I wonder if Crimea was granted to Ukraine as part of the negotiations that caused Ukraine to surrender its very large number of nukes to Russia between 1991 and 1996. If that is the case then a delay in providing the military aid Congress had approved would have been especially bitter to the Ukrainians. Since both Bush 1 and Clinton had been part of the process which stripped them of their strongest defense.
My impression is that there was a delay because President Trump wanted to make sure that the military aid would go to the correct place. If he didn't do that and the aid was sent immediately to the wrong hands, Ukrainians would not have received aid at all. Apparently obama had sent some aid but had it delivered to Poland so the Ukrainians had to go pick it up...and then there's the issue of blankets and meals sent by 0.
Fact is, Ukies received aid before the deadline.