Thank you for reaching out to us and apologies for the inconvenience
Test the speaker.
1. From the phone dialler, enter *#0283#.
2. Select LOOPBACK.
3. Select Start : SPK_2ndMic.
Say a few words as if you were on a call. If you hear your own voice on loudspeaker, it's working correctly. Try soft reset your device, press and hold the power and volume down buttons for about 10 to 15 seconds (this will not erase your data, it is just to reboot the device)
Also ensure that your software is updated