When trying to open Maxar data in QGIS, it often does not render properly out of the box.  This is because the band configuration needs to be set up properly and there are a few anomalies in the default settings.

Imagery without proper band settings

Setting bands in QGIS

Reordering bands

Maxar imagery comes in Blue Green Red NIR order.  Sometimes the bands are not labeled properly in the image, however so it can be confusing.  

1. Add Image to QGIS

2. Go to Image Properties / Symbology.  Configure as shown below:

Yes - you are correct, it says Band 3 is blue, but it is not.  Trust me here....

Disabling Transparency

The next default that needs to be addressed is the Transparency.  By default, QGIS thinks the fourth band is an Alpha band, but it is the NIR band.

1. Go to Image Properties / Transparency

2. Under Custom Transparency Options select None

3. Click OK at the bottom of the panel.

Image with proper band settings