MapboxGL maps do not match the projection when canvas aspect ratio is below 1.0

To reproduce:

• start the mapviewer example leaving the window size as is (360 x 640)
• select mapboxgl
• tilt the map
• pan around

the red dot and the label do not stick to their geo position.

If you enlarge the window to be 1:1 or larger A/R, things work as expected