NS8-traefik: Lost HTTP Routes after restoring traefik (Could not resolve traefik@node to an agent_id)

An in-place restore of traefik (replace existing app) resulted apparently in lost access to cluster-admin (it was not really the case, just worked with IP or FQDN on a private window).

I think the main problem is that traefik app instance is restored with a new name, HTTP routes are lost, and any other existing or new app are like in an unlinked state from traefik (or traefik “unlinked” from the node). Sorry, don’t know the right terms.

Apps still have their FQDN in their Settings, but with no HTTP routes all webapps are inaccessible.

Neither existing App Instances nor new ones can save Settings changes:

/home/dokuwiki16/.config/actions/configure-module/30traefik:51: UserWarning: Could not resolve traefik@node to an agent_id
  default_traefik_id = agent.resolve_agent_id('traefik@node')

I was trying to see what happens when changing the fqdn of an app, then restoring traefik (with old info) from backup.

Also it is possible to restore traefik from backup to a new instance on the same node, leaving the node with 2 unusable traefik instances
Traceback (most recent call last):
  File "/home/traefik2/.config/actions/list-routes/20readconfig", line 22, in <module>
    with urllib.request.urlopen(f'{api_path}/api/http/routers') as res:
  File "/usr/lib64/python3.11/urllib/request.py", line 216, in urlopen
    return opener.open(url, data, timeout)
  File "/usr/lib64/python3.11/urllib/request.py", line 525, in open
    response = meth(req, response)
  File "/usr/lib64/python3.11/urllib/request.py", line 634, in http_response
    response = self.parent.error(
  File "/usr/lib64/python3.11/urllib/request.py", line 563, in error
    return self._call_chain(*args)
  File "/usr/lib64/python3.11/urllib/request.py", line 496, in _call_chain
    result = func(*args)
  File "/usr/lib64/python3.11/urllib/request.py", line 643, in http_error_default
    raise HTTPError(req.full_url, code, msg, hdrs, fp)
urllib.error.HTTPError: HTTP Error 404: Not Found

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/traefik2/.config/actions/list-routes/20readconfig", line 25, in <module>
    raise Exception(f'Error reaching traefik daemon: {e.reason}')
Exception: Error reaching traefik daemon: Not Found