Yesterday I had some small camera issues, where the panning to the right was moving very slowly. After zooming out again ( I was zoomed in all the way into the structure of a building), the panning returned to normal speed. I think whenever this minor thing happens it is because of the point the camere is focused on.
It also happens sometimes when zoomed out, very occasionaly. After zooming in or out again the game returns to it's normal camera speed.
I found that the Camera gets "stuck" in Scenery. It doesn't completely stop, but it is significantly slower when the Camera is in the Hitbox of a Scenery Piece. I don't know why they did it that way. Maybe to have more precision while building and moving the Camera? I don't know. More often than not it is rather annoying than helpful.