Was using the app on MacOS and noticed that the rotation behavior was no longer intuitive using the right mouse button. Today opened the app on the iPad and found the same problem. I have a part opened and the view set to “top.” I put my finger on the x-axis near the origin and drag straight to the right along the x-axis. This should give nearly a pure rotation about the y-axis, but it does not, it mostly rotates the part about the z (vertical out of page) axis. I.e. an in-plane rotation.
However, if I drag my finger along the y-axis, the part does rotate around the x-axis as expected.
Due to the difference in how these two drags operate, when one combines them as one would in a free-form rotation, the results are completely unpredictable.