Hello@Jennys ,
Please confirm your Tapo APP and camera firmware are both up to date first, and here are some suggestions you could give it a try:
1. Try to switch between the night mode and day mode manually and hear if there is a click sound from camera?
2. Shake the camera and see if it will work properly.
3. Try to shine a light on the environment in Night Mode, are able to see any image
If still the same issue, can you help confirm some information here, thank you
a) MAC address, hardware version, firmware version of the camera. (please share MAC address to us via private message)
b) A picture of Live view when camera work Night mode / Day mode
c) APP version (Tapo APP-> Me-> About)
d) Band and model of the phone, OS version of the phone.