I am trying to capture HTTPS traffic from my rooted Android device (4.4.4) to analyze an undocumented protocol of an app. I've set up my Fiddler as a proxy and enabled HTTPS sniffing. I've installed the Fiddler's generated root certificate on my device. I've set up my proxy for my Wifi on my Android device.
When I run my browser and navigate to any HTTP or HTTPS site, Fiddler can capture traffic successfully.
When I run some apps (e.g. my own app which uses Parse as its backend), I can see all the HTTPS traffic to the servers, decrypted. So far so good.
When I try to run that particular app, I can't get Fiddler to capture its traffic. Here's all I get on Fiddler:
URLs are some IP addresses:SSL (:443).
I've also tried using ProxyDroid. Interestingly, I was able to capture the traffic once, saw a decrypted HTTPS connection to that app's servers, but after that, it never captured again. I know that the app uses HTTPS, and not an unknown/other protocol.
How can I capture HTTPS traffic successfully, and why would Fiddler once work for that app, and suddenly stop working?