Unable to send video

Hello together,

we have Rocket.Chat Server 0.69.1 on Ubuntu 16.04.5 LTS.
We can’t sent videos from the iOS App and from Android App.
On Android i managed to make a screenshot with the following message:
“Network Error: write error: SSL=0x7d9256d100: I/O error during system call, Broken pipe”
I tried WLAN and LTE Connection. Both the same problem.
The Client on Windows 10 / 7 works fine.
Does someone have the same problem and a solution?