Custom targets not found on Mbed Studio 1.4.4

Mbed Studio
1

Hello all, I ´m trying to create a custom target as I succesfully did a couple of years ago but now it became imposible.
In order to make it simple at first I have simply copied an existing target directory and renamed it, let say from NUCLEO-G474RE to NUCLEOS-G474RE (in the directory mbed-os\targets\TARGET_STM\TARGET_STM32G4\TARGET_STM32G474xE). I´ve modified the CMakeList.txt file entries to the new name. Once done I’ve tryed in two ways that worked for me in the past:
1.- Harcoding the targets.json copying the previos target and changing the name like this:

. . . . .
    "NUCLEO_G474RE": {
        "inherits": [
            "MCU_STM32G474xE"
        ],
        "supported_form_factors": [
            "ARDUINO_UNO"
        ],
        "overrides": {
            "hse_value": 24000000
        },
        "detect_code": [
            "0841"
        ],
        "device_name": "STM32G474RETx"
    },
    "NUCLEOS_G474RE": {
        "inherits": [
            "MCU_STM32G474xE"
        ],
        "supported_form_factors": [
            "ARDUINO_UNO"
        ],
        "overrides": {
            "hse_value": 24000000
        },
        "detect_code": [
            "0841"
        ],
        "device_name": "STM32G474RETx"
    },	
. . . . .

In this way I can not find the new target in Mbed Studio.

2.- Using custom_targets.json file like this:

{
    "NUCLEOS_G474RE": {
        "inherits": [
            "MCU_STM32G474xE"
        ],
        "supported_form_factors": [
            "ARDUINO_UNO"
        ],
        "overrides": {
            "hse_value": 24000000
        },
        "detect_code": [
            "0841"
        ],
        "device_name": "STM32G474RETx"
    }
}

In this way, target in not detected either.
If I remember well both ways worked fine for me in the past but I used first one as the seconds one broke the intellisense.

Do you see any problem with custom targets with latest Mbed Studio versions?

Thank you very much