When querying data through the PI Connector for PowerBI using Data Views, you are only able to use the default Interpolation Mode which is Continuous.

The Continuous Interpolation Mode returns interpolated data using previous and next index values. If either of the previous or next index values are null, then the returned value will be null as well. This means that if you are querying a timestamp that is later than the latest archived value in OCS, the return value will be null.

There are multiple Interpolation Modes available for read stream data, please make them available for the Data Views as well, specifically the ContinuousNullableLeading mode which returns interpolated data or data from the previous index if either of the surrounding indexes has a null value.