I believe Scheduled updates should work, but I probably did something wrong.
So, I created a smart computer group where I added my machine. Then, I opened software updates and tried to force macOS updates for this group (I have used different flags to force the update). My machine is Apple Silicon (m1). I don't see a proper way to check scheduled updates on my machine, so I use API (v1/managed-software-updates/plans) for it.
In answer, I see already 14 plans, and most of them failed with the error "EXISTING_PLAN_FOR_DEVICE_IN_PROGRESS" .
That means at least the plan should be executed, but nothing happened.
What did I do wrong?
{
  "totalCount" : 14,
  "results" : [ {
    "planUuid" : "09487431-7d17-4c4f-baa2-5b5d03f7c076",
    "device" : {
      "deviceId" : "579",
      "objectType" : "COMPUTER",
      "href" : "/v1/computers-inventory/579"
    },
    "updateAction" : "DOWNLOAD_INSTALL_SCHEDULE",
    "versionType" : "LATEST_MAJOR",
    "specificVersion" : null,
    "maxDeferrals" : 0,
    "forceInstallLocalDateTime" : "2024-01-26T13:55:31",
    "status" : {
      "state" : "PlanFailed",
      "errorReasons" : [ "EXISTING_PLAN_FOR_DEVICE_IN_PROGRESS" ]
    }
  }, {
    "planUuid" : "24d0e5be-c56a-46b7-9b7d-763fd4eafd7b",
    "device" : {
      "deviceId" : "579",
      "objectType" : "COMPUTER",
      "href" : "/v1/computers-inventory/579"
    },
    "updateAction" : "DOWNLOAD_INSTALL_RESTART",
    "versionType" : "LATEST_MAJOR",
    "specificVersion" : null,
    "maxDeferrals" : 0,
    "forceInstallLocalDateTime" : null,
    "status" : {
      "state" : "PlanFailed",
      "errorReasons" : [ "EXISTING_PLAN_FOR_DEVICE_IN_PROGRESS" ]
    }
  }, {
    "planUuid" : "30a79936-7785-471d-8b2a-24a4433888d6",
    "device" : {
      "deviceId" : "579",
      "objectType" : "COMPUTER",
      "href" : "/v1/computers-inventory/579"
    },
    "updateAction" : "DOWNLOAD_INSTALL_RESTART",
    "versionType" : "LATEST_ANY",
    "specificVersion" : null,
    "maxDeferrals" : 0,
    "forceInstallLocalDateTime" : null,
    "status" : {
      "state" : "PlanFailed",
      "errorReasons" : [ "EXISTING_PLAN_FOR_DEVICE_IN_PROGRESS" ]
    }
  }, {
    "planUuid" : "4d4b6ea0-3cd8-4267-9a4c-fca9761a7136",
    "device" : {
      "deviceId" : "579",
      "objectType" : "COMPUTER",
      "href" : "/v1/computers-inventory/579"
    },
    "updateAction" : "DOWNLOAD_INSTALL_SCHEDULE",
    "versionType" : "LATEST_MAJOR",
    "specificVersion" : null,
    "maxDeferrals" : 0,
    "forceInstallLocalDateTime" : "2024-01-26T12:54:31",
    "status" : {
      "state" : "PlanFailed",
      "errorReasons" : [ "EXISTING_PLAN_FOR_DEVICE_IN_PROGRESS" ]
    }
  }, {
    "planUuid" : "53de88d7-82a7-4665-87a1-a8d28469525f",
    "device" : {
      "deviceId" : "579",
      "objectType" : "COMPUTER",
      "href" : "/v1/computers-inventory/579"
    },
    "updateAction" : "DOWNLOAD_INSTALL_RESTART",
    "versionType" : "LATEST_MAJOR",
    "specificVersion" : null,
    "maxDeferrals" : 0,
    "forceInstallLocalDateTime" : null,
    "status" : {
      "state" : "PlanFailed",
      "errorReasons" : [ "EXISTING_PLAN_FOR_DEVICE_IN_PROGRESS" ]
    }
  }, {
    "planUuid" : "646611d8-0447-4f0b-9a58-4e15f581e44c",
    "device" : {
      "deviceId" : "579",
      "objectType" : "COMPUTER",
      "href" : "/v1/computers-inventory/579"
    },
    "updateAction" : "DOWNLOAD_INSTALL_RESTART",
    "versionType" : "LATEST_MAJOR",
    "specificVersion" : null,
    "maxDeferrals" : 0,
    "forceInstallLocalDateTime" : null,
    "status" : {
      "state" : "PlanFailed",
      "errorReasons" : [ "EXISTING_PLAN_FOR_DEVICE_IN_PROGRESS" ]
    }
  }, {
    "planUuid" : "9188b418-c82e-4030-9aaa-c205278b1614",
    "device" : {
      "deviceId" : "579",
      "objectType" : "COMPUTER",
      "href" : "/v1/computers-inventory/579"
    },
    "updateAction" : "DOWNLOAD_INSTALL_RESTART",
    "versionType" : "SPECIFIC_VERSION",
    "specificVersion" : "12.7.1",
    "maxDeferrals" : 0,
    "forceInstallLocalDateTime" : null,
    "status" : {
      "state" : "PlanFailed",
      "errorReasons" : [ "EXISTING_PLAN_FOR_DEVICE_IN_PROGRESS" ]
    }
  }, {
    "planUuid" : "acbaa0ed-88fd-425b-b91b-b2a642baeb9f",
    "device" : {
      "deviceId" : "579",
      "objectType" : "COMPUTER",
      "href" : "/v1/computers-inventory/579"
    },
    "updateAction" : "DOWNLOAD_INSTALL_RESTART",
    "versionType" : "LATEST_MAJOR",
    "specificVersion" : null,
    "maxDeferrals" : 0,
    "forceInstallLocalDateTime" : null,
    "status" : {
      "state" : "PlanFailed",
      "errorReasons" : [ "EXISTING_PLAN_FOR_DEVICE_IN_PROGRESS" ]
    }
  }, {
    "planUuid" : "b3f19c33-681f-408b-87a7-5db555ac3805",
    "device" : {
      "deviceId" : "579",
      "objectType" : "COMPUTER",
      "href" : "/v1/computers-inventory/579"
    },
    "updateAction" : "DOWNLOAD_INSTALL_SCHEDULE",
    "versionType" : "LATEST_MAJOR",
    "specificVersion" : null,
    "maxDeferrals" : 0,
    "forceInstallLocalDateTime" : "2024-01-26T12:54:31",
    "status" : {
      "state" : "PlanFailed",
      "errorReasons" : [ "EXISTING_PLAN_FOR_DEVICE_IN_PROGRESS" ]
    }
  }, {
    "planUuid" : "bb184902-f16a-4e92-ab96-a5f161ae93c3",
    "device" : {
      "deviceId" : "579",
      "objectType" : "COMPUTER",
      "href" : "/v1/computers-inventory/579"
    },
    "updateAction" : "DOWNLOAD_INSTALL_RESTART",
    "versionType" : "SPECIFIC_VERSION",
    "specificVersion" : "13.6.1",
    "maxDeferrals" : 0,
    "forceInstallLocalDateTime" : null,
    "status" : {
      "state" : "SchedulingScanForOSUpdates",
      "errorReasons" : [ ]
    }
  }, {
    "planUuid" : "c869cffa-3731-42a6-8f38-f4f5017468a9",
    "device" : {
      "deviceId" : "579",
      "objectType" : "COMPUTER",
      "href" : "/v1/computers-inventory/579"
    },
    "updateAction" : "DOWNLOAD_INSTALL_SCHEDULE",
    "versionType" : "LATEST_MAJOR",
    "specificVersion" : null,
    "maxDeferrals" : 0,
    "forceInstallLocalDateTime" : "2024-01-29T13:10:00",
    "status" : {
      "state" : "PlanFailed",
      "errorReasons" : [ "EXISTING_PLAN_FOR_DEVICE_IN_PROGRESS" ]
    }
  }, {
    "planUuid" : "caa65e7f-9844-4ba3-bb91-f26cd853b572",
    "device" : {
      "deviceId" : "579",
      "objectType" : "COMPUTER",
      "href" : "/v1/computers-inventory/579"
    },
    "updateAction" : "DOWNLOAD_INSTALL_RESTART",
    "versionType" : "SPECIFIC_VERSION",
    "specificVersion" : "13.6.1",
    "maxDeferrals" : 0,
    "forceInstallLocalDateTime" : null,
    "status" : {
      "state" : "PlanFailed",
      "errorReasons" : [ "EXISTING_PLAN_FOR_DEVICE_IN_PROGRESS" ]
    }
  }, {
    "planUuid" : "e30c93c8-2a7b-4a45-96ba-0fb404e90b58",
    "device" : {
      "deviceId" : "579",
      "objectType" : "COMPUTER",
      "href" : "/v1/computers-inventory/579"
    },
    "updateAction" : "DOWNLOAD_INSTALL",
    "versionType" : "LATEST_MAJOR",
    "specificVersion" : null,
    "maxDeferrals" : 0,
    "forceInstallLocalDateTime" : null,
    "status" : {
      "state" : "PlanFailed",
      "errorReasons" : [ "EXISTING_PLAN_FOR_DEVICE_IN_PROGRESS" ]
    }
  }, {
    "planUuid" : "faa6e753-50a8-4500-abe1-5b195330e92c",
    "device" : {
      "deviceId" : "579",
      "objectType" : "COMPUTER",
      "href" : "/v1/computers-inventory/579"
    },
    "updateAction" : "DOWNLOAD_INSTALL_SCHEDULE",
    "versionType" : "LATEST_MAJOR",
    "specificVersion" : null,
    "maxDeferrals" : 0,
    "forceInstallLocalDateTime" : "2024-01-26T13:50:31",
    "status" : {
      "state" : "PlanFailed",
      "errorReasons" : [ "EXISTING_PLAN_FOR_DEVICE_IN_PROGRESS" ]
    }
  } ]
}