This is because a strip footing or other structural support has been selected. Select a foundation beam.

Many errors appear after analysing the job: beam errors, insufficient column reinforcement, etc.

If the wall foundation consists of a strip footing (without external fixity) and the columns have been introduced with external fixity, differential settling occurs because the wall descends vertically as it has been assumed to bear on an element (foundation beam) which rests on springs (elastic bed). On the other hand, the columns’ vertical movement is fixed as these have been introduced with external fixity.