UP Studio 2.6 insists on adding a brim?

I have a simple model and selected “No Raft”, “No Support”.
When I slice the model the software insists on adding a brim or raft of some sort.

Yellow lines:

Here are the settings (couldn’t post 2 images in a single message due to forum rules…)

because the area around edge is not flat and not contacting the build surface. Software detected the gaps and add layers to fill the space. otherwise it will be printing on air.

how can it be printing on air and contacting the surface at the same time?

I mean it is not contacting platform, so software add some stuff to fill up the gap.