The 'All Bounding Boxes: pink boxes' option determines whether all object bounding boxes are displayed continuously. When selected (which is the default setting), it will consistently display bounding boxes for people, vehicles, and forklifts. When deselected (This can be deselected from the Live view>>Select camera>>search this camera>>All bounding box right corner).

It will show boxes if a specific object type is chosen (for instance, only people in this scenario).

So, if you deselect all filters, a bounding box will disappear. Similarly, if you conduct a video search and then deselect the bounding box option, it will vanish. Conversely, selecting 'people' or 'vehicle' will bring the boxes back into view.