"There is something weird in the kitchen."
Translation:هُناك شَيْء غَريب في ٱلْمَطْبَخ.
your sentence is correct, but this is how Duolingo works. I face the same thing in all languages I learn here mainly because contributors don't include every possible combination or order. Specially with Arabic; The choices are quite varied. This taught me to follow the order suggested by Duolingo as much as possible.
This said, sometimes an Arabic speaker would bring the attention to one specific element of the sentence by bringing it to the beginning - it can be grammatically correct, but it's just a "speech style" if i can call it.