Trying to get transformation between 2 arUcos

Hi, I’m woriking on a project where I have to obtain the pairwise transformations between arUcos on a box. I’m using OpenCV’s calibrateCamera() to calibrate my camera and I obtain 0.100 of reprojection error, which I believe is not bad. Then I use detectMarkers() to detect the arUcos on the box and then I use estimatePoseSingleMarkers() to estimate their pose with respect to the camera. I then use Rodrigues formula on rvecs and build the tranformation matrix with that. The problem is, the arUcos should have a 90º angle between them, and that’s not happening. The image bellow shows the image I’m using and the poses that I’m obtaining. (I changed the perspective so you can see better)

What can i do to corret this? What am I doing wrong? Thanks in advance