Have you ruled out the possibility that this is due to the remote control for some other device in the room being used?
The Hikvision NVRs and DVRs accept commands from an infra-red remote control.
Some are supplied with a remote, some are not.
It can happen that the infra-red signal from the remote control for another device e.g. your TV is received by the DVR/NVR but it cannot do what it is being asked to do.
Get a feel for whether it corresponds.
Put something in front of the DVR/NVR's front panel that will block any spurious remote control signals for a day or so and see whether this problem disappears.