P2P stopped working using cellular network

[nosnoop]

I have NVR 5216-16P-4KS2 and have been using iDMSS on my iPhone successfully with both P2P and VPN connection for the past few months.

In the past few days, I was not able to access the video using P2P when on LTE data. Strangely, the P2P works fine when using my home WiFi, but once I turned off WiFi on my iPhone, I only get "Fail to Connect" with P2P. Accessing using VPN continues to work fine. I don't mind using VPN, but my family finds P2P much more user friendly.

I have tried two different iPhones and two different cell phone networks (in Canada) with the same result.
Anyone else has this problem?

 

[nosnoop]

My initially thought was that it was related to cell phone network access, but actually, it did not work anywhere outside my home wifi network using P2P.

And it was caused by a bug in the iDMSS App.
They just released 3.51.001 today to fix this bug. Updated the App, and the problem is gone.

 

[daves52380]

I am having this problem now. Same NVR as you, just started using the system and im a noob. Work great with app while on home wifi, once turning off wifi. Cannot connect to anything thru the app. no preview, no playback, get "failure to connect" and cannot access any settings. I have NVR connected to network thru tp-link router using password protected wifi. I dont know anything about VPN that i hear people using. Not sure what I have to do to get this to work on cellular network.