https://en.wikipedia.org/wiki/Hyperinflation_in_Zimbabwe

From 1991 to 1996, the Zimbabwean Zanu-PF government of president Robert Mugabe embarked on an Economic Structural Adjustment Programme (ESAP) that had serious negative effects on Zimbabwe's economy. In the late 1990s, the government instituted land reforms intended to evict white landowners and place their holdings in the hands of black farmers. However, many of these "farmers" had no experience or training in farming.[6] From 1999 to 2009, the country experienced a sharp drop in food production and in all other sectors. The banking sector also collapsed, with farmers unable to obtain loans for capital development. Food output capacity fell 45%, manufacturing output 29% in 2005, 26% in 2006 and 28% in 2007, and unemployment rose to 80%.[7] Life expectancy dropped.[8]The Reserve Bank of Zimbabwe blamed the hyperinflation on economic sanctions imposed by the United States of America, the IMF and the European Union.[9][10] These sanctions affected the government of Zimbabwe,[11] asset freezes and visa denials targeted at 200 specific Zimbabweans closely tied to the Mugabe regime.[12] There were also restrictions placed on trade with Zimbabwe, by both individual businesses and the US Treasury Department's Office of Foreign Assets Control.[13]

the Mugabe government was printing money to finance involvement in the Democratic Republic of the Congo and, in 2000, in the Second Congo War, including higher salaries for army and government officials. Zimbabwe was under-reporting its war spending to the International Monetary Fund by perhaps $23 million a month.

This narrative really contrast that it's all about debts owed in foreign currency. Either way, even if Zimbabewe started with minimal foreign currency debt, the above would still have resulted in massive inflation because like you said, the economic capacity was too small at the time from the negative shock. But why would countries have foreign debt if not to use the borrowed money to spend on things? The are just faces of the same coin since that is what MMT implies about taxation and seigniorage.