OnePlus CEO Pete Lau apologized on Weibo on Friday for OnePlus 8 series phones running out of stock on all ecommerce platforms in China. Lau didn’t say whether it’s related to smartphone supply chain disruptions caused by the coronavirus pandemic. Instead, he said that the company underestimated demand for the new phones.

“This is caused by our lack of confidence for the product in the early stage, and we don’t have any excuses,” Lau said. “We apologize to all users and fans!”

It’s not clear how many units the company had in stock for the launch when the series went on sale in China on April 17, and the company hasn’t disclosed sales figures. But disappointing fans in China isn’t ideal as the company tries to appeal more to its home country after the pandemic disrupted global consumer demand and shipping.