addRow works, but setValue doesn't seem to work on added row

I’ve got a grid that adds a row. If I use grid.cells(id, c).setValue() the data appears, but getValue() doesn’t return anything, just an empty string.

for example:

grid.addRow(“test”, “”)
grid.cells(“test”, 4).getValue() == “”
grid.cells(“test”, 4).setValue(“hello”)
grid.cells(“test”, 4).getValue() == “” //still

I’m really trying to avoid a full grid refresh for adding rows. Is there some cache I need to clear out to get this to work?

What is a type of column in problematic case?
There are some kind of columns ( edn, ron for example ) which accepting only numeric data and will ignore string parameter.