Follow this **checklist** before

 1. Check both connection method, http/https connection methods can be different between browsers 
 2. Check (if possible) response status on your browser debugger
 3. Print all the request payload (headers/content/…) in your monitor (if the program reaches this point). Also you have to compare the first one of the good working phone, and the second with yours 

Then you’re may able to know if the problem comes on your program, or in your libraries, or in a wrong setup 

Looking at your logs, you can try to avoid the error by resetting manually the watchdog or disabling it for the *looptask*.