Encoder Zero does not persist after reboot

MDtool version: v1.5.3
CANdle library version: v3.5.3
Device firmware version: v2.2.1
MD Drive firmware version: v2.4.1

After configuring the Encoder Zero using `mdtool config zero <ID>` and saving using `mdtool config save <ID>` the setting does not persist when the motors are powered off. 

Is there a fix for this? 