Using an Apple iPhone, a FortiGate 60E (6.0.4 build0231) and a FortiAP FP221C (6.0-build0030), the sound and video often get out of sync. When this happens the voice continues normally while the video often freezes. The video does not go away but instead simply stays on the same image while the audio works properly. The out-of-sync issue happens with WiFi only or with both WiFi and cellular data turned on. This does not happen with only cellular data on. The common denominator regarding this problem seems to be with the WiFi turned on.
Websites alone (static web pages without video) are often slow to load as well whenever the WiFi is turned on.
Have others experienced this? Any ideal how to fix the problem?