Edge 1040 Solar. I have version 27:14. I have had a problem where I have not been notified to being off course even though these alerts are on. This happened at some critical times in the Pyrenees.

At certain critical times it did not notify me as being off course. 
not sure if it is a map setting or accuracy of satellite position.

in some cases it did give a warning but I was maybe 30m to one side but actually on the correct track. 

concerning was lack of warning when off track.