This issue is found os-migrate user.
Currently RHOSO18 shipped openstacksdk package lacks the following patch.

commit 9fc4b9f26aeee0ed157d21c47aaad600199b4dd4
Author: Rodion Gyrbu <rgyrbu@yandex.ru>
Date:   Wed Jun 21 16:29:45 2023 +0300

    Add missing `force` parameter
    
    Change-Id: I6c413cdb9001373d2f73ad9df56bb86dd51566ef

Due to that, every operation of volume snapshot when the volume is attached to the instance always fails.

This blocks the migration by os-migrate.

Bug impact

• This issue blocks tenant migration in customer site.

Known workaround

• Apply the fix by hand.

Additional context

• The issue happens with the specific combination.

The conditions are:
1. Source OpenStack version is RHOSP16.2
2. The conversion host uses RHOSO18's openstacksdk, python3-openstacksdk-1.0.2-18.0.20250130094655.eee309c.el9ost.noarch.rpm
3. The target instance of os-migrate is boot-from-volume.