In both November and December, ~5M 5G phones shipped in China. The monthly total is likely to go up quickly, as supplies of lower-priced phones are becoming widespread. In particular, the US$285 Xiaomi phone is now shipping. The December total phone sales were down 14% compared to Dec 2018, which may suggest people were waiting on the availability of less expensive 5G phones.
This is the official figure from the China Academy of Information and Communications Technology, CAICT. It is part of the Ministry of Industry and Information Technology (MIIT.) There have recently been inconsistencies in reports from China. Ten million "reserved" 5G in the first two weeks of October; a senior technical company expert expected they would get phones within a month.
That schedule hasn't been met. The Chinese press reported some supply shortages. Some people may have delayed purchasing phones as announcements were made of lower prices soon to come. I may have misunderstood press reports, which I read in Google translation. Some numbers could have been exaggerated.
China Mobile expects to sell ~100M 5G phones in 2020. China Telecom plans 60M. That's more than the official Chinese projection of a total of 150M in 2020, although China Unicom has not yet estimated publicly. I'll be watching closely to get accurate figures.