I would like to report a bug that effects the Surround Focus (Independent) settings, when I add manual distances of all speakers, it works well, however when I select Linkage from it and then go back to independent speakers, FR, FL, RR, RL distances disappear from it.
Please make it remember the distances entered and if possible, add up to 3 presets, for example, if I would like to change the focus from driver to passenger or rear, I could choose from the presets.

Also,
I can't select exactly 80hz on front and rear speakers for HPF (highlighted in blue), it always is either 77hz or 82hz, not in between, it doesn't show 80hz when I move slider. LPF on subwoofer channel can be selected (marked in red).

My Device: DUDU7 (8-128 9.5 inches) on latest 3.6E Final update. The above can be reproduced without the need for logs. Please test on your device.