Data map did not work properly

Hello experts,

I am facing a stupid thing and need help 🥲.

I am using data map to push data from CAPEX to FS cube. However, it did not work properly.

For example, my source data is blank/null in Oct, Nov, Dec:

But when I pushed data using a data map to the target cube, the target data showed 0 instead of blank/null:

I am not sure why it did not show blank/null.

My expectation is that it should display 'blank/null', not '0', here. Because my Account properties are set up to skip missing only for business requirements.