GIF Stream Works 50% of the Time

I use iPhone X running iOS 13.2 The GIF still images stream feeds every 4 to 5 seconds from Hikvision NVR off of 6 cameras. It works 50% to 60% of the time. But the Panel often fails to display any image from any cameras. When it works, all cameras’ images would refresh every few seconds, which is what I want. But when it doesn’t work, all I see is “blanks” for all cameras. It’s either “all or none”. The frustrating part is I have tested many different ways, I could not figure out the pattern why 50% of the time would fail. I tried to swipe up and kill the browser. Still no help. But if I wait for 20minutes or an hour, it would show up. Then, It would work for few times or 10 times, and when I go back, the images would NOT show up AGAIN. Then I would try again and again, it would continue to show nothing. I would just give up and wait for 20 minutes or an hour, and it would work again!! Does it have to do with iPhone Safari browser’s caching mechanism? Is this iOS or Safari limitation? Does anyone have similar experience? Is there a way to fix it to make it 100% working and reliable?

Below are 2 screen captures: the 1st is to show the times that don’t load the images. The 2nd is the one that “works”.