I have 5 of these throughout my house and they all work well as repeaters. As stated above your device will choose what it connects to. If they are close enough to connect well to your hub that can be difficult to get them to switch.
Something you can try is power down you hub completely for around 20 to 30 minutes. This will cause your battery devices to go into panic mode and look for a new connection. Sometimes this can help push things to repeaters.
Also, if your devices are working with no issues then don't worry about it. Put your repeaters in your mesh. Keep adding devices. Your hub when it starts to hit count will start shedding devices and pushing them to repeaters if they are in your mesh. At least that is how it was explained to me once.
Also, a wise man (@danabw ) once told me if your mesh is working fine then don't put a lot of stock in the zigbee maps. If it works it works and don't fix it.
