draftsight 2017 grips in dimensions

I installed draftsight 2017 & find that the grips are not working on dimensions. ie if I add a dimension then want to move the grip to another point it is not working. Well sometimes it does & other times not.

I have not consciously changed any settings & I cannot find any setting that relate to this 

I use this feature regularly so have re installed 2016 & it is back to working ok.

Any suggestions ?

Thanks