Not able to upload files with iPhone from external

Hello,

i am not able to upload files from my iPhone when the iPhone connects to Workspace from external. We deployed nginx as reverse proxy in our DMZ which forwards the requests to the internal Gateway VA.

The Upload starts (transferred bytes count up), then the tranfer terminates with "Error"

I could not find any errors in the logfiles, but maybe i did not look in the right places

If the iPhone is connected to Workspace from internal, the problem does not occur

Any ideas about that ?

Thank you