What's the correct term for ping (connection latency) in Standard Chinese/Cantonese? How would you say something like "I'm lagging again, my ping is spiking to 500(ms)" in Putonghua and Cantonese (in the context of online games)? I've heard someone say "網又卡了！" before, but I'm not entirely sure how common that is.
Yes, in putonghua，We say "网又卡了， 我ping都500了， 卡死了（damn lagging）， 你卡不？小王怎么一点都不卡呢？”

“Ping” is totally acceptable in Putonghua， just like “windows，NPC，BOSS”， all game players know it， or you can use "延迟”， “我延迟有500了” 。