Problem

The controls below should be next to each other, not below each other:

CSS of the elements shows

class="span[object Object] offset[object"

so obviously something's not being parsed correctly here.

Reported and analysed on Discord by @kantlivelong and @jneilliii (thanks!)

Solution

self.controlVM.rowCss is being called with a control object that still has observables as props instead of raw values. ControlViewModel.rowCss doesn't expect that however. The solution is to unpack the observable before handing it to ControlViewModel.rowCss.