On mac, mouse Zooming into an objects seems to stop working randomly when getting close to an object. Panning also seems to stop working also.
yep, you are inside the limit of your current camera frustum
select the part you are zooming into, then type zoom, and choose selected. this will refocus the camera with a smaller field of view and you will then be able to zoom in closer.
I have a hotkey for zoom selected and it’s useful if you are working on small parts of a large model.