Where the function is intended for
A user notices seconds of delay via mobile internet, while the image on a local monitor is almost immediate. That difference makes the route more important than just the camera.
advice
Investigate Dahua image delay
Lagged image can occur in the camera, recorder, network or watching phone; therefore, one test on one app says little.
Setting or condition
Compare the same channel locally, on internal Wi-Fi, and via mobile internet. Note the resolution, streaming choice, and whether the delay occurs with all cameras or only with one channel.
Making a conscious choice
Only after comparison adjust the relevant bottleneck: network load, stream profile, device or a specific camera setting. Do not reduce image quality without knowing which route the delay causes.
What you check afterwards
Repeat the three viewing tests after a change and compare the recording with live footage. Document the chosen stream setting so that later it is clear why it was used.
Frequently asked questions
Does delay always come from slow internet?
No. Local network, recorder or device can also play a role.
Is lower resolution the best solution?
Only when the test shows that bandwidth is the limitation.