My pixel 4a phone fights me !
I used an Esp32-cam board to send video steam , using its own AP.
Connecting to the site 192.168.4.1 works with Pc on Chrome browser, on Iphone and on Samsung phone on Chrome.
It does not load on my Pixel - not on Chrome or Firefox or Brave browsers. It does not load with b4a webview.
I removed the safe browsing protection in the settings - still not working.
I have tried the same myself when I got my ESP32CAM to work (the initial camera was faulty) and I have got the same results (not with Google pixel - I do not have one). I used the provided by Arduino IDE example with the ESP32CAM web server. What I noticed in the B4A app (I used the CCTV example) was that it is confused in the barrier If I recall correctly but I never got it working.
Might be related to the cellular network. Try to disable the data connection (put the device in airplane mode and enable wifi if there is no such option).