There seem to be many problems with keyboard layout switching in Ubuntu.
For me (Ubuntu with Gnome Shell), it used to work until version 13.10, maybe 14.04. Currently I am on 15.04.
Even then Alt+Shift would work but for some reason layout started to switch also using Left Shift+Right Shift which is greatly annoying because I tend to press this combination inadvertently when typing.
In Settings -> Keyboard -> Shortcuts -> Typing, "Modifiers-only switch to next source" is set to Alt+Shift. All the other options there are unset.
Where else can you set the layout switching shortcuts?
In some questions and answers I see people referring to the "Text Entry" app - I don't see it anywhere, I guess it was changed in later versions?
Also, I don't know if this is related, in "Input Method Configuration", I see the following:
Active configuration: ibus (normally missing)
Number of valid choices: 2 (normally 1)
Available input methods: ibus xim
Unless you really need them all, please make sure to install only one input method tool.
Another problem is that the switching layouts doesn't work well. Sometimes I have to switch three times before it actually switches. Also the indicator shows the wrong language. I usually have two layouts: en and cs. Sometimes the indicator shows en while the layout is cs, or even the other way around I guess. It's all just a mess.
Is there a way to reconfigure/reset the layout switching, a way to start from scratch?
Is there some official Ubuntu guide? Does it work better in other distros? Maybe there's a relevant guide for ArchLinux?