That's absolutely normal. The scenery range it's 16 NM so, you just entered in the loading range, and the pause is the scenery loading its objects, KLAX is fairly complex, so the pause might be more noticeable than other sceneries.
You can control this a bit, by setting the Anti-pop up value of the Addon Manager to an higher value.
But, this won't change anything that happens at 16 NM. If anything, raising the Anti-pop up might even increase the pause BUT, there won't be any other loading pauses. Instead, lowering it up to its default value (1), might decrease the loading pause at 16 NM, at the cost of having other minor pauses when going closer, due to the delayed loading of smaller object. At the maximum value, *everything* will be loaded at 16 NM.
The setting is there, because most users would prefer having a single pause in the distance, and then a smooth approach, rather than a shorter pause initially, but followed by several smaller pauses when on final.
So, basically, the total time of the pause will be always there, you can only choose if you want to have a single big pause, or several smaller ones.