Insert data to grid in acumatica - acumatica

Question

I have a grid (show the devices) and action MATERIALS (a grid in a smart panel - show the materials of each device).
In an action Get Devices (code below), I want to load devices from another table to this grid also materials of each device to smart panel MATERIALS.
After the action is executed, just the devices are shown. The panel MATERIALS doesn't have any record, I try to press the Refresh button but there still doesn't have data.
The magic is that after I press Save button in the header, data in MATERIALS is shown correctly.
public PXAction<PSMTPhieuYeuCauSuaChuaMHTBHeader> GetDevices;
[PXUIField(DisplayName = "Get Devices")]
[PXButton(CommitChanges = true)]
protected void getDevices()
{
PSMTRequestRepairMaint thisGraph = PXGraph.CreateInstance<PSMTRequestRepairMaint>();
foreach (var record in PSMTPhieuYeuCauSuaChuaMMTBDeviceSelectedView.Cache.Updated)
{
PSMTPhieuYeuCauSuaChuaMMTBViewDevice device = (PSMTPhieuYeuCauSuaChuaMMTBViewDevice)record;
if (device.Check.HasValue && device.Check.Value)
{
PSMTPhieuYeuCauSuaChuaMMTBLineGrid line = (PSMTPhieuYeuCauSuaChuaMMTBLineGrid)thisGraph.PSMTPhieuYeuCauSuaChuaMMTBLineGridView.Cache.CreateInstance();
line = PSMTPhieuYeuCauSuaChuaMMTBLineGridView.Insert(line);
line.DeviceID = device.HeaderID;
line.FromDate = device.LastMaintenanceDate;
line.ToDate = device.LastMaintenanceDate;
device.Check = false;
line = PSMTPhieuYeuCauSuaChuaMMTBLineGridView.Update(line);
var materials = PXSelect<PSMTAllowedReplacementMaterial,
Where<PSMTAllowedReplacementMaterial.headerID,
Equal<Required<PSMTPhieuYeuCauSuaChuaMHTBHeader.soMay>>>>.Select(this, line.DeviceID);
foreach (var item in materials)
{
var allowedMaterial = (PSMTAllowedReplacementMaterial)item;
PSMTPhieuYeuCauSuaChuaMMTBMaterial material = (PSMTPhieuYeuCauSuaChuaMMTBMaterial)thisGraph.PSMTPhieuYeuCauSuaChuaMMTBMaterialView.Cache.CreateCopy(new PSMTPhieuYeuCauSuaChuaMMTBMaterial());
material = PSMTPhieuYeuCauSuaChuaMMTBMaterialView.Insert(material);
//material.LineGridID = line.GridID;
material.MaterialID = allowedMaterial.MaterialID;
material.Quantity = allowedMaterial.Quantity;
material = PSMTPhieuYeuCauSuaChuaMMTBMaterialView.Update(material);
}
}
}
}
Grid
Panel