There is no bug – if any place that contains an observation has it marked introduced, it will show introduced.
Theoretically, to have this observation show not introduced, either the boundary for the Alps needs to be modified to not include this place, or the status in the Alps needs to be modified to not be introduced. However, the Alps is too large to modify, so in practice the only way to not show introduced on this observation is to removed the introduced status in the Alps.
Generally speaking, it’s not a great idea to add a status to a large place that has both native and introduced populations. Adding the status at a smaller level is usually a better idea.