For some odd reason when I am connected to my 2.4GHz network on my iPhone 6S I get a high ping usually between 100 - 200ms. It only happens on my iPhone 6S, all other devices when connected to the 2.4GHz network get a ping usually around 13 - 15ms. But when i'm connected to other 2.4GHz networks (e.g. Coffee Shop, Shopping Centre, etc.) on my iPhone 6S I get a low ping. So it's only happening on my iPhone 6S on my 2.4GHz network. I get good speeds on the 2.4GHz network, it's only the ping that is bad. When I connect my iPhone 6S to my 5GHz network I get a ping usually between 13 - 18ms. I am using the Advanced Wi-Fi Modem. I have tried changing Wi-Fi channels, resetting the modem and resetting the network settings on my phone but the ping doesn't get any better. What are some steps I could try to fix this issue?