LR 6.14; windows 10; Develop; Crop & Straighten Always crops

This can happen when you have chosen an aspect ratio within the camera menu, that differs from the native aspect ratio of the sensor. Could that be it?

Typically: with camera JPG the camera will hard-crop the processed image that it makes, to this user chosen aspect ratio; but with camera Raw (if implemented at all) this is just a soft crop. So you will then have the opportunity to reverse or change it - all of the sensor's picture coverage having been included in the file you've imported, regardless.

Otherwise, the application of lens (geometric) corrections or automatic levelling (for example) can lead to a reduction from the overall 'Raw captured' image extent.