Dx35 Why does the speed setting automatically change to "Expert”?

The parameters are all stored correctly and remain permanently in the sensor. The only exception is index 103 - this index switches to "Expert".

Details regarding the speed setting:

There is a dependency from index 103 (response time) to:

• Index 64: integration time

• Index 66: bit filter for switching output

• Index 67: averaging
   

For a speed setting of e.g. "Slow", the indices 64; 66 and 67 have pre-defined values.
With devices with firmware version < V2.2.0 it was not possible to change the values 64; 66 and 67 manually when the speed setting was "Slow". Before that, "Expert" had to be selected for index 103. "Only writeable, if "0: Expert" was selected for index 103". Consequently, index 103 was dominant in these devices.
For devices with firmware version ≥ V2.2.0 , this condition no longer exists. For example, you can select "Slow" for Index 103 and then change Index 64. If this is done, Index 103 is automatically set to "Expert".

This is exactly what happens now in the case of a backup.
The parameters of the sensor are rewritten during import. First index 103 is set to e.g. "Slow" and then the parameters for index 64, 66 and 67 are entered (corresponding to the "Slow" default setting). As soon as these are entered, index 103 is set to "Expert" again. At this moment, however, no check is performed (here is the small inconsistency) whether the entered parameters for Index 64, 66 and 67 belong to a predefined speed.
 

In brief:

The parameters of the required indices correspond to the actually selected speed, but "Expert" instead of "Slow" is output on index 103.
Below is a table showing the individual speed settings and their default settings in "Expert" Mode.
Here you can also check once again whether the corresponding pre-settings match.