For my part.
If I do not display the current values in the web page, there is a problem with the configuration.

For engines that the value does not change, I redo a configuration in another location (in the config.g), I think there are conflicts following the instructions that are used later.

In my case, I had a problem with extruders on the DUEX5, which remained at 0mA, while on the DUET the command worked.
Putting this line further in the code corrected the problem.

M906 E800:800 ; Set motor currents (mA);pour test>> necessaire sinon pas de courant du tout