Auto Changer not recognized

We got a new hardware backup server and installed Cyberprotect 15 on Windows 2022

The tape drive of the changer is recognized, the changer itself is not recognized. I opened a ticket with highest priority (we cant backup to tape!) last week with Acronis support and got no answer. I can't reach anyone with the chat and I was for 30 min on hold on the UK phone support just to hear that no one is available.

The tape is recognized in Windows, the drivers for both tape and library are installed. The library was working fine with CP 15 on the old backup server.

CP does only see the drive
 

C:\IT\HP>acronis_tape_hcl_Windows_x64.exe
Welcome to Acronis Hardware Compatibility Tool for Tape Devices.
Error 0x15003eb: Invalid XML tag '/arsm_devices/autoinventory'.
| line: 0x40cfe291a9083af2
| file: h:\arsm2\enterprise\rsm\configuration\impl\xml_config_loader.cpp:101
| function: `anonymous-namespace'::XmlTagProcessor::ProcessChildren
| $module: acronis_tape_hcl_static_vsa64_s_9106
C:\IT\HP>tapes.exe
Found tape \\.\tape0

C:\IT\HP>mtx_test.exe
Tape Drives:
  Drive:
    Path:      "\\?\scsi#sequential&ven_hp&prod_ultrium_6-scsi#5&1adff154&0&00fa00#{53f5630b-b6bf-11d0-94f2-00a0c91efb8b}"
    Vendor:    "HP"
    Product:   "Ultrium 6-SCSI"
    Revision:  "354W"
    Serial:    "HUJ5113B1V"
    Has media: no
    CartridgeType:   LTO-CVE
    CartridgeFormat: Ultrium 6/16T
    Capacity:        2500000 Mb

Changers:
  None.

We need a remote session of a good technician to help us here. We followed the guide at Acronis Cyber Backup Advanced: Troubleshooting Tape Detection Issues | Knowledge Base and the changer is not recognized.