The formula function “isblank” doesn’t seem to be able to determine if a number field is empty. I’m guessing formulas consider empty number fields to be zero, which results in the “isblank” function saying that the field is not blank, because it has a value of zero. But this means there is no way to determine the difference between a blank number field and a non-blank one with a value of zero.
Tested this locally and I can confirm that
isblank doesn’t work with number fields.
There is a related issue already for rating field having the same problem (isblank() function doesn't work for Rating field type (#996) · Issues · Bram Wiepjes / baserow · GitLab)
@nigel do you know if supporting different field types for that function is feasible?