Hi Iván,
Thanks for contacting Syncfusion support.
We have prepared the Grid CRUD action sample by using remoteSaveAdaptor. But unfortunately, the reported issue was not reproduced at our end. We suspect that you did not return the newly added record properly from the controller to Grid. So, please ensure this case in your project. You can use the browser network tab to ensure returned values.
Also, we have attached our sample in the below link for your convenience. So, please refer this sample for more details
If you face the same issue after referred our sample, then please share your Grid code, CRUD action code, Syncfusion script version and network tab response screenshot to us. This will help us to provide a better solution for this issue as early as possible.
Regards,
Hariharan