This is an issue I have run into only now.
The Problem
When using snapping, the distance between objects is not shown when moving them with the mouse while guides are enabled
Nudging does show distances
Distances are shown when not moving along guides
How to reproduce
Enable column guides
Add a rectangle and match the width with that of the column guide
Make a copy and move vertically below with snapping enabled
Distance will not show
Move rectangle copy horizontally on the same height as the first rectangle
Distance is now shown when moving
What I made sure of
Snapping and snapping candidates are enabled and work
All extra options are set (show gaps and sizes e.g.)
To try and find a solution - without success
Additional Info
I am using Windows 10 64-bit Home
Affinity Designer is at version 1.7.2.471
2019-09-03_00-26-26.mp4