AMBIENT LIGHT REJECTING SCREENS SUCK.
Accept this as a reality. They DO the job that they are designed for. A proper ALR screen will reject ambient light and improve contrast significantly.
What nobody talks about is that this doesn't come for free. You introduce hot-spotting, image uniformity issues, and sparkling/shimmering into the image when you use a ALR screen. As well, many ALR screens are negative gain, often heavily negative gain, which takes away from potential brightness and makes the already weak HDR of projection even worse. Ultra short throw ALR screens are much better about reducing this issue, but they still aren't great as many are .6 gain or worse, taking away nearly half the light output of the projector.
Controlling light in the room is critical for best image quality.
You can introduce some lighting away from the screen area if desired to move around and do things in other areas. Lighting near seating locations and in other parts of the space should be controlled for best results, but it will impact the image. Windows are tough if not light locked during the day. Any actual sunlight coming through a window really can make an image unwatchable without a ALR screen.
There are some images on some forums of setups with sunlight in rooms and what happens when rooms are darkened completely. I have a set of photos up when lighting is added to a space right here:
http://www.avintegrated.com/lighting html