Product and version: FMPA 16.0.3
OS and version: macOS 10.13.3 beta 4 [17D34a]
Hardware: MBP 13" Retina Late 2013
Description: In Layout Mode, using Tab-Key in Inspector to define Position used to jump from Left to Top to Right … Width Height.
With current High Sierra Beta, it additionally jumps into field for unity (pt. / in / cm).
How to replicate: Layout-Mode, select a object, Toggle thru 'Position' with Tab-Key
Workaround: Hit Tab-Key twice to move from one Inspector Field to another