IOS/iPhone Can't connect under 4G/5G network

Same mobile carrier, Android can play mediasoup webrtc stream but iPhone can’t. If Iphone switch to wifi, it can play webrtc stream again. mediasoup demo has the same issue. anyone kindly help me out?
Thanks in advance.

fixed by deploying a turnserver.

Is this mobile carrier ipv6 only? I can confirm that mediasoup works fine with both Android and iOS clients without the use of a TURN server. But, some mobile networks will force the connections through ipv4/ipv6 NATs which don’t always work well with WebRTC.

Thank you for your clarification. Turn server is the last means.