Fbe200 doesn't save audio options


have 2 fbe200-h264lan , firmware e264-20180408

i connect hdmi camera and receive rtsp stream. Video is fine, but audio is very metallic. I see in media options that audio is from hdmi input, volumne default, resample disable, audio encode aac-lc , 48kbps
i think the problem is with low bitrate (48kbps) , but whatever option I change, I click APPLY , i get confirmation message, reboot the machine and options go back to default, even without reboot if i change page and go back to media page my changes are lost.