The issue
Cluey uses the GPS of your smartphone to record your location. In some circumstances, these GPS-systems have difficulty to make a proper GPS-fix. In these cases, your latest known position or the location of a nearby cellphone tower is being recorded instead.
Solutions
1) Use the Zoom on me function to check on the map whether the GPS-fix corresponds with your current location. You may have to repeat this, if the GPS is not responding directly.
2) Zoom in on the map and long-press the position where you want to create the Observation.