Thanks for the answer. It is not 12Mbps, but 100Mbps. The speed is about 12M/s. However, it is not a bandwidth problem. Even if I increase the bandwidth to 1000M in the settings, it still only displays 480p on iOS. On the contrary, when I tested on Android, even if I lowered the bandwidth to 1M in the settings, all options were still displayed. Obviously this is a problem with the ios app.
