Sven AC MS-1085 lost one channel

In these columns it is possible to connect headphones directly to it (and that principle is conveniently). A couple of months everything was fine but then I updated the BIOS ( and sorry to roll it back is also not ( officially)), and after disconnecting the headphones from the speakers lost the right channel, helps juggling wires (quite a chore). How can I fix this problem?
My configuration:
CPU: AMD 1600 Ryzen
GPU: Palit nvidia gtx 1060
RAM: G. Skill Trident Z RGB 2х8gb 3200 MHz
Motherboard: MSI Gaming B350 Pro Carbon (never msi)
PSU: Corsar rm650x
Speakers: Sven AC MS-1085
Headphones: HyperX Cloud Core