So far, the Chinese civil aviation authority has not given the Boeing 737 Max a re-approval. The manufacturer flew a Max-7201 to Shanghai with the N7S. This should support the test procedure.
China is behaving cautiously due to the two crashes and, unlike the FAA and EASA, has not yet given the green light. This is definitely problematic for the aircraft manufacturer, because this state in particular is considered a particularly important sales market. Boeing is now making a 737-Max-7 available to the local aviation authority for test purposes.
Official China should be able to check the modifications to the aircraft and also carry out test flights. However, security concerns are clearly not the only reason for the delays, as a trade conflict has been simmering between the United States and China for a long time. So it is not surprising that the US pattern is not given priority. At most, China - like EASA and Canada - insists on carrying out its own test flights with its own pilots.