Can't set region from CLI

Other settings work, but I can’t set the lora.region setting on the latest firmware 2.5.6 and cli version 2.5.3. Device is a Heltec WSL v3.

xx@xx:~$ meshtastic --factory-reset
Connected to radio
INFO file:node.py factoryReset line:644 Telling node to factory reset (config reset)
xx@xx:~$ meshtastic --set lora.region 'EU_868'
Connected to radio
Set lora.region to EU_868
Writing modified preferences to device
xx@xx:~$ meshtastic --info | grep region
    "region": "UNSET",

What am I doing wrong here?