Error with exec command fired from Node-Red

I’m running Node-Red with Home Assistant on Raspberry Pi.
From Node-Red I fire the the following command:
‘echo ds2482 0x18 > /sys/bus/i2c/devices/i2c-1/new_device’
to initialise 1-wire reading.

Earlier this was working without errors but now I get the following error message:
/bin/bash: line 1: /sys/bus/i2c/devices/i2c-1/new_device: “Read-only file system”

If I run
‘echo ds2482 0x18 > /sys/bus/i2c/devices/i2c-1/new_device’
from the terminal, it works just fine.

The problem has started rather recently but I don’t know which operating system or Home Assistant or Node-Red version has starting to make this error.
The problem seems to be related with file-access rights.
Any explanation?