Files are not fully downloaded or damaged

I have an Android app that downloads files from the server from time to time Tomcat7 running on RedHat Linux

. The server is under my control and only authorized users can download it. The files are information about the database and can be quite large, only 4.8Mb. However, even small files cannot be downloaded completely.

These files have been downloaded in the past in the past, but have started to download fully recently. I don't know if the problem is on the server or client side. Server bandwidth usage ~ 10%.

I am looking for a guide on how to identify a server issue or issue in an android app. I have searched for hours trying to find anything that could be related without success.

I don't know if this is related, but SecureCopy (SCP) stops frequency on this server.