dcmsend fails: cannot negotiate network associaion: DUL Association Rejected

How to reproduce

From the server where Kaapana is deployed I run dcmsend command with any data (that I worked with before). I used the command from the UploadView.

Expected behavior

Data are sent successfully.

Actual behavior

Data are not send successfully.

System information

• Ubuntu OpenStack Instance -> master

Logs from operators or containers

Using FQDN or IP

dcmsend -v vm-131-124.cloud.dkfz-heidelberg.de 11112 --scan-directories --aetitle kp-testdata --call kp-admin --scan-pattern '*.dcm' --recurse SM/
I: determining input files ...
I: checking input files ...
I: starting association #1
I: initializing network ...
I: negotiating network association ...
I: Requesting Association
F: cannot negotiate network association: DUL Association Rejected

Using localhost:

dcmsend -v localhost 11112 --scan-directories --aetitle kp-testdata --call kp-admin --scan-pattern '*.dcm' --recurse SM/
I: determining input files ...
I: checking input files ...
I: starting association #1
I: initializing network ...
I: negotiating network association ...
I: Requesting Association
I: Association Accepted (Max Send PDV: 16340)
I: sending SOP instances ...
I: Sending C-STORE Request (MsgID 1, VLw)
I: Received C-STORE Response (Success)
I: Sending C-STORE Request (MsgID 2, VLw)
I: Received C-STORE Response (Success)
I: Sending C-STORE Request (MsgID 3, VLw)
I: Received C-STORE Response (Success)
I: Sending C-STORE Request (MsgID 4, VLw)
I: Received C-STORE Response (Success)
I: Sending C-STORE Request (MsgID 5, VLw)
I: Received C-STORE Response (Success)
I: Sending C-STORE Request (MsgID 6, VLw)
I: Received C-STORE Response (Success)
I: Sending C-STORE Request (MsgID 7, VLw)
I: Received C-STORE Response (Success)
I: Sending C-STORE Request (MsgID 8, VLw)
I: Received C-STORE Response (Success)
I: Sending C-STORE Request (MsgID 9, VLw)
I: Received C-STORE Response (Success)
I: Sending C-STORE Request (MsgID 10, VLw)
I: Received C-STORE Response (Success)
I: Sending C-STORE Request (MsgID 11, VLw)
I: Received C-STORE Response (Success)
I: Sending C-STORE Request (MsgID 12, VLw)
I: Received C-STORE Response (Success)
I: Sending C-STORE Request (MsgID 13, VLw)
I: Received C-STORE Response (Success)
I: Sending C-STORE Request (MsgID 14, VLw)
I: Received C-STORE Response (Success)
I: Releasing Association
I: 
I: Status Summary
I: --------------
I: Number of associations   : 1
I: Number of pres. contexts : 1
I: Number of SOP instances  : 14
I: - sent to the peer       : 14
I:   * with status SUCCESS  : 14