You installed your floor properly as long as it is maintaining the minimum gap at the door, but you needed also make room for a transition strip which requires about an inch of room from the door.
To include a transition strip I made my cut about 1 inch away from the surface where the transition strip was to go. Then the metal track that holds the transition strip in place still allow the 1/2 inch minimum required for the transition strip and the floor to work together. After setting the transition strip in place it cover the edge of the floor and kept the minimum requirements needed for they allow for the expansion and contraction. I included a few pictures to show what I have left.
Since there was no clean way in my eye to terminate the transition strip, I let it run from trim edge to trim edge as Illustrated one picture but since it blended in with the flow of the floor, it is not highlighted very well. I included another picture that I have not trimmed out yet
I do not have any pics of the process, but some of the space was too tight on some of the doors and needed to be cut in place. I used a multi-tool and a straight edge to do this but it can be done with a razor knife with much care and a straight edge. I also modified the transition strip to make it more narrow. I do not like transitions strips as it is, but the nature of the floor requires them