Re: "So how much of the final payment was in cash? I'm hoping at least half. "
Given that the documented reason for the delay was "The Buyer cited the wide-ranging impacts that COVID-19 has had on businesses globally and the lengthy administrative process associated with transfers of funds outside of China.", I'd say half is fair in that the delay was likely only one half of the time to get the funds outside of China.
Or, as we suspected, maybe there was a different reason.
Good luck!!