Layer not fixed when creating print layout

[Mark Ambrose]

I've done a search for this but I may be using the wrong terms, so if this has been covered, please let me know.

• I've created a couple of vector layers and added them to an additional project.  
• I've gone to layout and selected one that I've been using for the project 
• When I go to 'add map', the layers I've added are not in the correct position on the base map (I've tried Sixmap and Google)
• As I zoom in and out, the layers move in relation to the base map (or the other way around, I'm not sure!)
• As far as I know, I haven't changed any settings since last using this layout.  I have tried closing and reopening, creating a new layout and doing the same on a colleagues PC, all with the same result. Any ideas?