M or F visa to work in China?

My husband and I live in South Africa. We have worked in China for 4 years. We were unable to go back to China before the expiration of our temporary resident permits due to the pandemic. Our institution wants us to inquire if we could apply for an M or F visa in order to go back to China when the borders are opened. Is this okay? Or should we still apply for a Z visa like we did the first time we applied?