Issue after updating to iOS12 (IP Cam Viewer Lite)

[happy2005k]

I have been using IP Cam Viewer Lite for a while, it works great. Thank you.

However, after updating my iPhone to iOS12 recently, one of 4 channels stopped showing up. The one not showing is random.
My CCTV system is Zmodo 8-channel DVR, it's a very old box, the manufacturer no longer has App for it.

Not sure if this issue is caused by the Lite or by iOS12. Please help.