How to change HM-10 Tx Power?

I am using HM-10 as iBeacon and the Tx Power is set to -59 by default. I want to change the Tx Power and the datasheet said that AT+MEAS can be used to set iBeacon measured power. After calibrating my BLE RSSI at 1 meter was -23dBm which is E9 in hexadecimals. So I tried changing the Tx Power using commands AT+MEASFFE9 and AT+MEAS0xFFE9 but I did not get any response form the BLE. So how can I change the Tx Power of my BLE?
If I set it up as a beacon and open an BLE Location app then the RSSI is always -45dBm or -46dBm even if I am 5 meters away. Why is that so?

Here is the datasheet: