In some cases after mating parts and using the reposition tool, the gizmo arrows do not change the location of the part to its corresponding axis (note: it only does this about 10% of the time after mating a part, the rest of the time it works as intended)
Also the gizmo tool size sometimes changes in size and it becomes very small or huge.
1) Mate a part to another
2) use reposition tool, notice arrows change movement along another axist and not its own
3) if it works as intended un-mate the part and mate it again and repeat until bug occurs.
as I said the tool works well for the most part, the bug only occurs intermittently and only after playing 0.7 Beta.
Picture is of the part for which the bug occured.
This happened to me today and forgot to report it, I'm glad you've done it :D