Not null constraint not met when multiple values selected in drop down selector widget

[raherin]

When using the 'Value relation' widget and the 'Allow multiple selections' option is selected and the 'Not null' constraint is used, the app will fail to record the values selected if multiple values are chosen. The "Field should not be empty" error will show if the user selects multiple values in the drop-down menu. In order to remove the error message, the user must open the menu again and deselect one of the options and then select it again:

Screen_Recording_20240510_182332.mp4

I have created a project to demonstrate the error: support/drop-menu-test

To reproduce the problem:

1. download the project on the mobile app
2. open the project
3. press the 'Add' button to record a new feature
4. press 'Record' to create the feature
5. click on the drop-down menu on the 'path' field
6. select multiple options and press 'Confirm selection'
7. the 'Field should not be empty' error will show
8. reopen the drop-down menu
9. deselect one of the options and then select it again
10. press 'Confirm selection'

[jozef-budac]

I was not able to simulate the problem on the current 2024.2.0 RC. @raherin , can you also verify, that it is fixed?