Help! Orbiting around all three axis

I’ve had this problem for about 3 months now: and it happens in every new file I make. When I right-click to orbit in a normal, perspective window the orbit appears to be rotating all around all axes. The horizon plane becomes skewed. Entire orbit (right click) is very sensitive and rotates without much control.
This even occurs after I do ZS. In that case I will orbit around with the selected object in the center but will tilt even the ground plane. Any ideas?
Thanks. I am running Rhino for MAC 5.3.1

try going to Preferences -> View…

under Rotate, select ‘rotate around world axes’.

thanks so much! I think that did the trick.