Can't configure Remote Home Assistant

I’m trying to set up a second home assistant in a remote location and get it to talk to my main instance using the Remote Home Assistant integration but when I try to configure the remote instance i get a message saying: Config flow could not be loaded: 500 Internal Server Error Server got itself in trouble

The log shows this:

Logger: aiohttp.server
Source: data_entry_flow.py:380
First occurred: 2:47:17 PM (1 occurrences)
Last logged: 2:47:17 PM

Error handling request
Traceback (most recent call last):
  File "/usr/local/lib/python3.10/site-packages/aiohttp/web_protocol.py", line 435, in _handle_request
    resp = await request_handler(request)
  File "/usr/local/lib/python3.10/site-packages/aiohttp/web_app.py", line 504, in _handle
    resp = await handler(request)
  File "/usr/local/lib/python3.10/site-packages/aiohttp/web_middlewares.py", line 117, in impl
    return await handler(request)
  File "/usr/src/homeassistant/homeassistant/components/http/security_filter.py", line 60, in security_filter_middleware
    return await handler(request)
  File "/usr/src/homeassistant/homeassistant/components/http/forwarded.py", line 222, in forwarded_middleware
    return await handler(request)
  File "/usr/src/homeassistant/homeassistant/components/http/request_context.py", line 28, in request_context_middleware
    return await handler(request)
  File "/usr/src/homeassistant/homeassistant/components/http/ban.py", line 82, in ban_middleware
    return await handler(request)
  File "/usr/src/homeassistant/homeassistant/components/http/auth.py", line 236, in auth_middleware
    return await handler(request)
  File "/usr/src/homeassistant/homeassistant/components/http/view.py", line 136, in handle
    result = await result
  File "/usr/src/homeassistant/homeassistant/components/config/config_entries.py", line 218, in post
    return await super().post(request)
  File "/usr/src/homeassistant/homeassistant/components/http/data_validator.py", line 73, in wrapper
    result = await method(view, request, data, *args, **kwargs)
  File "/usr/src/homeassistant/homeassistant/helpers/data_entry_flow.py", line 71, in post
    result = await self._flow_mgr.async_init(
  File "/usr/src/homeassistant/homeassistant/data_entry_flow.py", line 225, in async_init
    flow, result = await task
  File "/usr/src/homeassistant/homeassistant/data_entry_flow.py", line 252, in _async_init
    result = await self._async_handle_step(flow, flow.init_step, data, init_done)
  File "/usr/src/homeassistant/homeassistant/data_entry_flow.py", line 380, in _async_handle_step
    if not isinstance(result["type"], FlowResultType):
TypeError: 'NoneType' object is not subscriptable

I checked the github page and others seem to have the same issue but no solution.

Looking at the stack trace, it does not seem to be in any of the code for the remote home assistant. Is this a known Home Assistant problem? I am using the NginX reverse proxy.