In my recent work I used a space station with kind of "wheels" which is originally in an upright position. Since I wanted to create a flyby along its rotating rings I rotated the whole object by 90° along its x-axis to easily move the camera along the model.
But after I did that, the green rotation handle was gone, and it was impossible to make the "wheel" rotate. Even typing in values didn't work. Changing values in the y- and z-axis produced the same rotation.
Whereas if you initially rotate the model by 90° using the z-axis, all the handles are there, and you can rotate the wheel.
I attached a simple example file for testing: rotate the model 90° along the x-axis and then try to rotate the wheel.