Field disappear from the Form View but The dropdown menu works good

[AlfredoChavez]

Hi, I am fairly new in appsheet.
The problem I got is I have a Form View with a dropdown menu. The Valid If expression which produce the dropdown menu is
SELECT(Proveedores Asignados[Proveedor],[Cod Req]=[_THISROW].[TRAZA])
The dropdown menu works good, it shows all the options according to the Valid If expression but after I choose one of the options the field disappear from the Form View. it is supposed it should remain over it.
I have recorded the record and everything is saved in the database except the value of the field that disappears.
There is a field in the database that is formed by concatenating the field that disappears with the value of another field, in this concatenated field the value that disappears does appear.

I have been trying to work out it by myself without success.
Thanks in advance for your help

[TeeSee1]

Could you share a screenshot of the column definition in full so we better can see what might be causing the issue?

[Marc_Dillon]

Typically, the reason a field may disappear, is because it has become un-editable by some other input.

Which field is disappearing? How is this [TRAZA] field being populated? Is the field disappearing when you enter something into [TRAZA]?

[nghilttran]

I also encountered the same situation as you but have no solution