App not connecting to Internet on certain phones

[benja8151]

Hello,

I am very new when it comes to Android development and I'm having some really frustrating issues. I'm basically trying to access MySQL database through my app (developed in Unity) and while pretty much everything works on my computer, when .apk is installed on my phone (Mi A2) or my collegue's Huawei, it seems to be unable to access the Internet. I have searched for threads of similar issues and have already set Internet access to "Require" in Player Settings. Manifest file also seems to contain the required line
<uses-permission android:name="android.permission.INTERNET"/>
. What's even more frustrating is that if I test the app on Bluestacks it manages to establish the connection, and it also works on Samsung S8. As far as I can tell there are no settings which would block internet access on first two phones.

I really can't find what could be the problem so I'm hopeful some of you might have more clue.

I'm not sure if it's common to post .apks here, but on this link: https://www.mediafire.com/file/rusr76y170anc5s/database.apk/file is the .apk of a test application which checks if internet access is available, if anyone wants to try it out. It's not used to access my database but rather to test which phones are unable to connect to Internet.

 

[benja8151]

I've tested it on Redmi Note 5 aswell, no success. From what I gather, the only common thing between these phones is Android 9 (and of course that they're all chinese value phones ). Is it possible that Android Pie really is the problem?