Container creation error

[Juan Moyano]

When creating a container with:
zun create nginx

I'm getting:
ERROR: b'Internal Server Error (HTTP 500) (Request-ID: req-fcd2580a-b9d7-4c8c-bee7-6382cef92a83)'

After that, if I run zun list, I'm getting the new container listed, but it remains stuck at status 'Creating':
| eb60fc2a-638d-4d71-a168-229ae61e20de | rho-2-container | nginx | Creating | None | | [] |

I'm attaching the outputs of:
journalctl -u devstack@zun-api
journalctl -u devstack@zun-compute

In both cases, it seems that the problem is the following:
AttributeError: module 'oslo_utils.timeutils' has no attribute 'strtime'

-OS:
Ubuntu 20.04.4 LTS
-OpenStack Installation from Devstack repo:
https://opendev.org/openstack/devstack
-Relevant local.conf options:
enable_plugin zun https://opendev.org/openstack/zun $TARGET_BRANCH
enable_plugin zun-tempest-plugin https://opendev.org/openstack/zun-tempest-plugin
enable_plugin devstack-plugin-container https://opendev.org/openstack/devstack-plugin-container $TARGET_BRANCH
ENABLE_CONTAINERD_CRI=True
KURYR_CAPABILITY_SCOPE=global
KURYR_PROCESS_EXTERNAL_CONNECTIVITY=False
enable_plugin kuryr-libnetwork https://opendev.org/openstack/kuryr-libnetwork $TARGET_BRANCH
LIBS_FROM_GIT="python-zunclient"
enable_plugin zun-ui https://opendev.org/openstack/zun-ui $TARGET_BRANCH