protozoan

This is expected behavior.

You can do it like this: Put a generic file name into the point cloud file parameter, like pcloud.0001.bgeo.sc

Append a edit material properties LOP after your material library.
Point its primpattern to your point cloud reader primitive, for example /materials/karmamaterial/kma_pcread1/

Press the "Create parameters" button, the parameters of that primitive will now appear underneath and can be modified.

Modify the point cloud file parameter to include the frame token, like pcloud.$F4.bgeo.sc

If you look at it in the geometry spreadsheet, you can now see that when you move on the timeline it will correctly update the primitive parameter.

A simplistic example file is attached.

If by "zoom" you mean in the viewport only, without changing the actual render output (for example to see something you edit bigger and more clearly): On the left side of the viewport, there is a 'view' icon (small camera icon), if you right click that, you can change the mode from "3D camera" to "2D pan and zoom" which lets you zoom and pan around in the view as needed.

If I had to guess I'd say that someone accidentally yanked the plug out of the wall that updates the changelog