Unable to import OVA/OVF into XCP-ng (xenserver). Failed to import error?

Question

virtual box

Good afternoon! Tell me who is in the subject. I'm trying to import virtual machines in OVA / OVF format on xcp-ng, everything is interrupted at 2-4 minutes with a Failed to import error.
The events for this task say:
1) Import VMs...
2) Connecting virtual disk OS-disk001.vmdk...
3) Failed to import.
And that's it.
The problematic server on xcp 8.1.0 I go through xcp center 20.04.

Tried bare vmdk and vhd, import fails with the same error. But xva exported with xcp 7.6 flew without problems.
Tried to import the same virtual machines on xcp 7.6, xcp center 8.0.1. Imported without problems.
If I try to import from xcp center 20.04 to xcp 7.6, I also get a Failed to import error.
And xcp center 8.0.1 no longer connects to xcp 8.1.0, while other xcp center 99.XX and 20.XX give the same error.

In the internet, I did not find anything on the latest XEN and XCP, respectively.
In general, the question is: how to import OVA / OVF virtual machines on xcp 8.1.0 directly, without converting?