Update missing from GUID data type field in From

[Friso]

I'm running into an issue that I'm not able to update or insert a value on CRM lookup fields, with a PowerApp form. My App is connected through CDS to a Dynamics 365 for Sales environment. When trying to create or update records, using forms, lookup fields (data type Guid) are not editable. Normal text, date and number fields work fine.

Creating a custom card also doesn't work because I'm still missing the update setting. I uploaded a picture that shows the difference between the data types.

Does anyone know how to get around this issue?