Hi Appian team, i've met a weird issue today. i'm not sure whether

Hi Appian team,
i've met a weird issue today. i'm not sure whether it is a common case or not. i'm using appian 6.71

in my model, there are several grids in one User Input task and the grid contains some boolean input.
i was trying to prevent the gird from showing the default empty row.
i was told the empty row shows because the boolean input has default value.

so i tried set null as default value to boolean input. it did work in my POC model which is used for testing.
but it did not work in my project model. empty row still shows and even i copy the same User input task from my POC model to project model.
this is the first weird point.

next i created a empty process variable which was a boolean type. i used it as a default value for boolean input in the grid.
it worked in one grid in first User input task but did not work in one grid in the second User Input task. i did not save any value into this empty boolean process variable.
i created a...

OriginalPostID-79995

OriginalPostID-79995