Moving a sensor to a new location in the same room is perfectly fine and you might find that some locations work better than others. The pairing of the sensor and the vent or vents will not be affected and the sensor will automatically reconnect to the hub once it is plugged in at its new location.
If you want to move a sensor to a different room, you must:
Disconnect the sensor through the Room Settings in the Ecovent app
Reset the sensor by using the reset tool (located on the back of your hub), or a paperclip and press it into the pinhole button on its left side prior to installing the sensor in a new room.
Unplug the sensor and plug it into its new room
Then follow the instructions to add a new room