Update, 3d connexion today's released driver 10.6.6 still causes unanted random shifting in max 2020 and 2021, all you need to do is draw a box, add camera, shift the lens, then select and inselect the box 3 or 4 times in the viewport and watch the camera shift on itself. Goodbye my NZD $1000 3d mouse :(
Seems to work better for me now (max 2020 sp3), but I can still fuck it up if I use the spacemouse on the camera when it has automatic tilt enabled, but I can't recreate it as you describe by just clicking in the viewport (I sure had it on the older driver version, but more randomly. Will have to monitor this, but fingers crossed! Have you tried going back to v.10.6.0? Seemed more stable to me on this issue. Also now seems like you can undo these buggy vert tilt camera moves done with the spacemouse? - It's all off topic for the corona daily discussion, so I think you/we should continue this over on the 3dconnexion forum :)