Error 409 when controlling a TV via SmartThings API

I have a user that is trying to control his TV via my code. The code is retrieving all the required settings just fine but sending any command fails with an error 409. For example:

* PostURL url: devices/device id is here/commands
* PostUrl body: {"commands":[{"component":"main","capability":"mediaInputSource","command":"setInputSource","arguments":["HDMI1"]}]}
* HTTPS Error: 409:

Any idea why he is getting that error code and how to fix it?

Thanks

Hi, @AdyR

Has this user tried to send a command directly to the device using other tools or does it happen with every command to it?
OCF devices don’t work on the API level but on the plugin level (ST app), here’s more info about that.
So, there are some commands that might not behave as expected or be accepted, it seems there are no issues with the syntax.
If it happens with every tool, for example, the user could try to use the ST CLI, then, it is being rejected by the device. Here’s an example of that command:

smartthings devices:commands deviceID "main:mediaInputSource:setInputSource(\"HDMI1\")"