you probably face this issue on all apple products. as a member of this forum, i've seen a lot of people talking about "false alarm" from the large ping attack that resulted from apple products.someone analyzed and located it to apple devices. 
well, i recently came across some articles about this. 
apple introduced a new mechanism back in ios 13. at that time, they added a new feature to actively detect your internet connection by randomly ping-ing their domain to test your connectivity. it's probing. 
what i dug from the article is that: netcts.cdn-apple.com 
apple products ping it at a rather large packet size and this triggers the alarm on omada gateway.
i searched this around but i don't see a lot of people mentioning this domain. i am not sure if it is active or not on ios 16. but it explains why you see large ping attacks from apple products.
so, it is not a true threat. and something can be done to get this better fixed. like a white list on the ping test? 
 

btw, does anyone know an official article or explanation from apple about this probing feature? i did not search on apple docs. maybe this is a dev blog? apple seems never released any details about this. it's a feature builtin to all apple devices since ios 13.