Hmm… I’m not familiar with OpenCV, but one guess might be that it doesn’t use the same coordinate system as does Panda.
For example, it may be that they use “y” where we use “z” and vice versa.
In fact, based on a quick search of the forum, it does look like that’s at least one problem. See the following post, in which the original poster seems to have figured out translation, but not rotation–the opposite of your problem:
