This is the first report of that kind. RadTabStrip control actually uses an inherited toolbox Panel control to host the corresponding controls in each TabItems (refers to TabItem.ContentPanel property), and neither Panel nor RadTabStrip have any strange logic for layouts. There is a possibility though, that controls' layout change if you have different DPI setting on the development and the other machines. In this case please let us know. In either case you should better open a support ticket and send us any code that might help. Also screenshots of both correct and incorrect controls' layout could be useful.
All the best,
the Telerik team