Distance for keyless entry remote?

I have just replaced the remotes on my 97 GP, and I can't get it to work much further than about 5 feet from the car.

I had a Bonneville, and a Suburban, and they both seem to work from a much longer distance, 40 or 50 ft.

I have replaced the battery, reprogrammed and still no change.

Has anyone run into this issue, and if so what fixed it?

By the way, I also have a 95 Z28 with the same issue.

Thanks for any clues.

Walter