'LeftShift+RightShift' switches layout although it's not configured to
I have a new Ubuntu 18.04 with Gnome 3.28.1 installed on my laptop, and I run into a problem.
I have set
Alt+Shift on keyboard layout switching, but
LeftShift+RightShift combo also triggers the switching, and I just can't find out why.
I have used
gnome-tweak-tool for the configuring, and I can guarantee that there is no ticks on the checkbox
Both Shifts together. As for built-in
Settings -> Devices -> Keyboard -> Typing, they have been set to
Disabled and therefore can't interfere.
Also, I checked
dconf-editor, and it shows
grp:alt_shift_toggle as it should, there is no mention of
grp:shifts_toggle at all. But it still switches a layout, and it just makes me mad.
However, if I disable
Alt-Shift as a layout-switcher,
LeftShift+RightShift also disappears, so it seems
grp:shifts_toggle is a sort of "backup value" or "repeater" of
There are some links where people had encountered with the same, but no solution was found.