I just opened my brand new Arlo 3 and it's missing one magnetic mount and the mounting screws and mount itself. Pretty sad. It was a sealed box. I called Arlo support and woman told me I need to return to Best Buy.....why not just send me a new one guys? Horrible!
It's not the end of the world. I'd stop by Best Buy and see if they would just take one out of another box. Another call to support to specifically request the missing mount may be successful, too.
You could also use a threaded mount.
Not really the best thing to do, by taking parts out of another package. Someone else will end up buying that, it happened to me a couple of months ago. Mine was missing the charger/power adapter and cable, returned it for refund (had other problems as well). But it’s not acceptable to find out not all parts are there when you open the package. This problem was reported by others as well, just makes you wonder about Arlo’s product packaging procedures.