There is an option in the GUI to change it but it does not work. I have popping issues when using HDMI audio and have read that Linux forces the hdmi into 44800 and needs to be 44100 for hdmi. The default on Lakka is 44800. I assume I can change it in the cfg files just giving a heads up that the one feature is not working correctly.
Maybe you need to restart RA to make this setting effective? I’m not sure. The default works for me on hdmi.