Have you saved the profiles when it was working? try loading them.

Could also be just IMU that needs calibration.

On worst case you need to read the users manual and perform the complete setting.

It is new technology, but not much more complicated that the menus of new cameras. Updated Metabones Speedbooster last night, now it supports focusing with EF lenses on GH4. Now trying GH4 focusing at the first time, and have no idea what is doing, I would just want centre point focus at half press (mostly for photos, but could be useful for setting the focus for video...) Anyway I was going trough the menus last night, and could not figure it out. I suppose I need to read the user's manual today.

You could try the get the files/settings from seller or someone, but they are somewhat firmware specific...

The users manual is now days quite ok http://www.basecamelectronics.com/files/v3/SimpleBGC_32bit_manual_2_50_eng.pdf

Just follow it carefully, to do the complete setup, and it should be ok. You will anyway need to learn how to balance the gimbal and tune PID when changing camera/lens.