I did some more digging into the American Thinker column I posted above. I'm not sure the author is accurate as to every claim; but I am certain about several things. I suggest reading the following article.
https://www.rollcall.com/news/policy/how-the-omb-used-its-powers-to-delay-ukraine-aid1. We are talking about the process called "obligating the funds." This means that the contracts necessary to spend the funds are signed and approved before the money is spent. This is not a case where the appropriated funds are wire transferred in bulk to Ukraine. The actual spending of the funds might not occur until next year, but those dollars would come from the federal government's fiscal year 2019 budget - not the current FY 2020 budget.
2. The OMB order was an apportionment order that was issued on the same day as the phone call, July 25th. An apportionment order is issued to review whether the appropriated funds should be spent exactly as proposed or whether the funds should be spent in different amounts on different things. The Ukraine law mandates 4 reviews per year on apportionment of appropriated funds. An apportionment review cannot block the spending of the appropriated funds.
3. If the President wants to block the spending of the money, he must seek a rescission of the appropriation from Congress. And Congress must approve such a rescission. While some people claim that rescission was discussed as to Ukraine, it was never requested.
4. On September 11th, the State Department certified to OMB that its portion, $141.5 million, of the Ukraine funds under apportionment review, were ready for obligation.
5. On September 12th, OMB released its verbal hold on the $250 million of security assistance and the $141.5 million of aid through the State Department.
6. By September 30, 2019, most all of these appropriations were obligated.
7. Trump requested another $250 million of security assistance for Ukraine in his FY 2020 budget request.
Thus, what we are talking about is an OMB freeze on releasing funds for obligation; but, at the same time, OMB was telling the DoD and State Department to continue preparing for obligating these funds before the end of the fiscal year. And, we are talking about a situation in which these funds most likely would not have been obligated for spending until near the end of the prior fiscal year anyway.
A number of Congressmen of both parties didn't like the slowness of the apportionment process and started complaining to OMB and to the media.
Senator Ron Johnson's letter to HPSCI states clearly that by late August, the Trump administration had decided to release the Ukraine funds for obligation. When Johnson asked Trump about it, Trump said that we were close to a decision and that he (Johnson) would like the result.
Thus, it appears that we are talking about an authorized and legal apportionment process for the aid that took longer than some wanted it to take. And that sparked a mini political spat. However, even if the funds had been released from the OMB hold for apportionment review in mid-August, they most likely would not have been obligated for spending until mid to late September anyway. Finally, obligation of the funds did not mean that the funds were actually sent to Ukraine. It just meant that these funds were allocated for use in various spending tranches for specific things and for disbursement at some later time.