Ongoing COVID-19 lockdowns and worker unrest at Apple’s (AAPL) manufacturing plant in Zhengzhou, China are leading to a shortfall of six million iPhone Pro models for sale in the global market.

The iPhone shortfall comes as Apple heads into the critical holiday sales period. The main issue is that Foxconn Technology Group, the Taiwanese company that operates Apple’s Chinese manufacturing plant, is struggling to get people back to assembly lines after violent protests against COVID-19 restrictions over the past week.

Government imposed lockdowns at the Apple manufacturing plant also continue to disrupt production and have led workers to protest and clash with police. Thousands of staff have fled the iPhone production campus, claiming a shortage of food and substandard quarantine practices.

The Foxconn manufacturing complex hosts as many as 200,000 workers during peak iPhone production. More than 20,000 new hires are reported to have left during the recent protests.

Foxconn’s China facility produces the majority of Apple’s newest iPhone 14 Pro and Pro Max devices, which were expected to be big sellers this Christmas season. Apple has now lowered its global production target to about 87 million units from an earlier projection of 90 million units.

Apple has said that it hopes to make up the iPhone shortfall in 2023, assuming the situation with COVID-19 stabilizes in China, a country with 1.4 billion people.

Apple’s stock is down 21% this year and trading at $144.22 U.S. per share.