I think I found a bug related to responsive layout when there is a login module in sidecol-a or -b.
When 'Sidecolumn Positioning' is set to 'Before Component' everything works normally. But when you change it to 'After Component' you can't fill your username and password in login module. The mobile keyboard disappears immediately after it pops up.

I have tested this with different login modules and the problem persists. If I move the login module to any other module position on same page, or positioning is set 'Before Component', it works normally with mobile device. Any ideas how to fix this?