Number fields can't be left empty

[jfr3000]

Describe the bug
When I have an empty number field, and edit any other field, the number field gets filled with "0". When I try to delete that value again, it displays NaN. I'd like to be able to leave number fields empty.

To Reproduce
Make a row with a text and a number field. Edit the text field in the edit view. The number field gets filled with 0.

Expected behavior
Number field should stay empty.