Convert2RHEL failing when converting via Satellite repo

I've been attempting to convert hosts (both CentOS 7 and CentOS 8) to RHEL using Convert2RHEL, pointing at our Satellite infrastructure:

# convert2rhel -o our-org -t org-rhel8-nonprod --debug

The conversion gets halfway through until the point where it checks for kernel modules being available in the new repo:

[11/04/2021 17:58:35] TASK - [Convert: Subscription Manager - Enable RHEL repositories] *********
[11/04/2021 17:58:35] DEBUG - Calling command 'subscription-manager repos --enable=rhel-8-for-x86_64-baseos-rpms --enable=rhel-8-for-x86_64-appstream-rpms'
Repositories enabled through subscription-manager

[11/04/2021 17:58:38] TASK - [Convert: Final system checks before main conversion] **************
[11/04/2021 17:58:38] DEBUG - Getting a list of loaded kernel modules.
[11/04/2021 17:58:38] DEBUG - Calling command 'lsmod'
[11/04/2021 17:58:38] DEBUG - Calling command 'modinfo -F filename vsock_loopback'

but alas, at this point it crashes out because the repomd.xml file it's attempting to pull from Pulp is 404:

[11/04/2021 17:58:38] DEBUG - Calling command 'modinfo -F filename fuse'
[11/04/2021 17:58:38] DEBUG - Calling command 'repoquery --releasever=8.4 --setopt=module_platform_id=platform:el8 --repoid rhel-8-for-x86_64-baseos-rpms --repoid rhel-8-for-x86_64-appstream-rpms -f /lib/modules/*.ko*'
[11/04/2021 17:58:40] DEBUG - Output of the previous repoquery command:
Updating Subscription Management repositories.
Red Hat Enterprise Linux 8 for x86_64 - BaseOS  1.3 kB/s | 224  B     00:00
Errors during downloading metadata for repository 'rhel-8-for-x86_64-baseos-rpms':
  - Status code: 404 for https://satellite.[domain.removed]/pulp/repos/our-org/Our-Org/Universal/content/dist/rhel8/8.4/x86_64/baseos/os/repodata/repomd.xml (IP: 172.31.242.15)
Error: Failed to download metadata for repo 'rhel-8-for-x86_64-baseos-rpms': Cannot download repomd.xml: Cannot download repodata/repomd.xml: All mirrors were tried

CRITICAL - No packages containing kernel modules available in the enabled repositories (rhel-8-for-x86_64-baseos-rpms, rhel-8-for-x86_64-appstream-rpms).
[11/04/2021 17:58:40] DEBUG - Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/convert2rhel/main.py", line 91, in main
    pre_ponr_conversion()
  File "/usr/lib/python3.6/site-packages/convert2rhel/main.py", line 209, in pre_ponr_conversion
    checks.perform_pre_ponr_checks()
  File "/usr/lib/python3.6/site-packages/convert2rhel/checks.py", line 57, in perform_pre_ponr_checks
    ensure_compatibility_of_kmods()
  File "/usr/lib/python3.6/site-packages/convert2rhel/checks.py", line 186, in ensure_compatibility_of_kmods
    rhel_supported_kmods = get_rhel_supported_kmods()
  File "/usr/lib/python3.6/site-packages/convert2rhel/checks.py", line 261, in get_rhel_supported_kmods
    ", ".join(system_info.get_enabled_rhel_repos())
  File "/usr/lib/python3.6/site-packages/convert2rhel/logger.py", line 104, in _critical
    sys.exit(msg)
SystemExit: No packages containing kernel modules available in the enabled repositories (rhel-8-for-x86_64-baseos-rpms, rhel-8-for-x86_64-appstream-rpms).

WARNING - Abnormal exit! Performing rollback ...

I've been banging my head against this for a day now and just can't figure it out. Everything else works fine - we can provision RHEL hosts from Satellite, and so on. My searches haven't turned up this problem elsewhere, although it's possibly my search skills just aren't that good.

Has anyone else seen this issue / can advise on how to work around it?

Thanks!
Mike