A recent flash in the night sky in New South Wales is believed to have been China's Shiyan-10 satellite. According to Space.com executing an expected upper rocket burn.

 A new object was catalogued in orbit and was likely this satellite but China have since declared it lost.

References

Mathewson, Samantha (September 30, 2021). Chinese satellite declared lost following back-to-back launches Monday. Space.com.

7 News Sydney [@7NewsSydney]. A flash in the night sky over New South Wales last night is believed to be a space rocket launched by China. Twitter.