Hi, I have no idea if this turns out to be a bug or something else.
I am trying to get a duration for tracked routes using the following:
I have a geopackage with a Linestring layer and I have Include M values ticked when creating the layer.
In this layer the line objects from Tracking are stored.
One of the fields (integer type) is called duration.
I would like to populate this field with the duration of the track, so I use the expression
m(end_point(@geometry))
This will return the m value of the last vertex and with the default QField tracking setting for m values (elapsed time), this gives me the duration.
Now, when I use this expression in the Attributes Form as Default value (with or without checking the Apply default on update box), QField is having problems with the internal positioning in such a way that it thinks my position is at random times suddenly more than 50 meters away and jumping back.
When I remove the default setting in the Attributes form, QField seems to be okay. I notice no weird behaviour. M values are being stored, so I can add duration afterwards in QGIS.
Could it be that the expression using end_point(@geometry) has an issue with tracking where end_point might no be clear all the time?
This is on a google pixel 8 phone and QField 4.0.5