Reading the situation
A dome, bullet, outdoor model or PoE camera may have different mounting and power requirements. Live image does not automatically mean that recording, export, playback or an existing NVR works in the desired way.
A Dahua system is only manageable when the camera, power supply, PoE, recorder or XVR, recording and users are considered as one chain.

A dome, bullet, outdoor model or PoE camera may have different mounting and power requirements. Live image does not automatically mean that recording, export, playback or an existing NVR works in the desired way.
Note the exact models, firmware, channel names, and existing connections. Determine whether the question is about installation, replacement, expansion, maintenance, or a malfunction. Then, first check the layer where the chain still works.
Modify carefully and test one camera or channel before adjusting the entire system. When expanding or replacing, compare power supply, PoE budget, recorder capacity, storage, and desired features; when exporting or licensing, keep personal accounts separate.
Check live view, recording, timeline, relevant event and view back with the normal user. Document model, channel, change and any limitation, so management does not remain dependent on the latest technician or one phone.
No. Exact model, firmware, channel capacity and desired features must be checked per combination.
Live connection, recording plan, storage and event linking are separate parts of the system.