Unable to delete mobile users

Hi,

i got an issue while trying to delete mobile user. The following is the log shown while doing delete action

2021-02-17 19:05:19,004 ERROR Internal Server Error: /a/fmoh-echis/settings/users/commcare/delete/cdbbbb81516b4026a6d35046d10e7005/
Traceback (most recent call last):
File "/home/cchq/www/echis/releases/2021-02-11_19.06/python_env-3.6/lib/python3.6/site-packages/django/core/handlers/exception.py", line 34, in inner
response = get_response(request)
File "/home/cchq/www/echis/releases/2021-02-11_19.06/python_env-3.6/lib/python3.6/site-packages/django/core/handlers/base.py", line 115, in _get_response
response = self.process_exception_by_middleware(e, request)
File "/home/cchq/www/echis/releases/2021-02-11_19.06/python_env-3.6/lib/python3.6/site-packages/django/core/handlers/base.py", line 113, in _get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/home/cchq/www/echis/releases/2021-02-11_19.06/python_env-3.6/lib/python3.6/site-packages/sentry_sdk/integrations/django/views.py", line 67, in sentry_wrappe$
_callback
return callback(request, *args, **kwargs)
File "/home/cchq/www/echis/releases/2021-02-11_19.06/corehq/apps/domain/decorators.py", line 106, in _inner
return call_view()
File "/home/cchq/www/echis/releases/2021-02-11_19.06/corehq/apps/domain/decorators.py", line 80, in call_view
def call_view(): return view_func(req, domain_name, *args, **kwargs)
File "/home/cchq/www/echis/releases/2021-02-11_19.06/corehq/apps/users/decorators.py", line 45, in _inner
return view_func(request, domain, *args, **kwargs)
File "/home/cchq/www/echis/releases/2021-02-11_19.06/python_env-3.6/lib/python3.6/site-packages/django/views/decorators/http.py", line 40, in inner
return func(request, *args, **kwargs)
File "/home/cchq/www/echis/releases/2021-02-11_19.06/corehq/apps/users/views/mobile/users.py", line 436, in delete_commcare_user
user.retire(deleted_by=request.user, deleted_via=USER_CHANGE_VIA_WEB)
File "/home/cchq/www/echis/releases/2021-02-11_19.06/corehq/apps/users/models.py", line 1954, in retire
self.save()
File "/home/cchq/www/echis/releases/2021-02-11_19.06/corehq/apps/users/models.py", line 1769, in save
super(CommCareUser, self).save(fire_signals=fire_signals, **params)
File "/home/cchq/www/echis/releases/2021-02-11_19.06/corehq/apps/users/models.py", line 1540, in save
raise self.Inconsistent("CouchUser with username %s already exists" % self.username)
corehq.apps.users.models.CouchUser.Inconsistent: CouchUser with username training.hew110@fmoh-echis.commcarehq.org already exists