Trying to install Home Assistant core on Raspbian Bullseye

Hi I took the plunge today to upgrade my pi from Buster to Bullseye.
I created a home assistant backup to eventually restore from.

So I’m using a new SD card, and followed all the installation instructions of HA Core from
https://www.home-assistant.io/installation/raspberrypi

I’ve gotten as far as running hass, but I’m getting the following errors in a constant stream: -

2022-09-04 18:30:29.188 ERROR (MainThread) [aiohttp.server] Error handling request
Traceback (most recent call last):
  File "/srv/homeassistant/lib/python3.9/site-packages/aiohttp/web_protocol.py", line 334, in data_received
    messages, upgraded, tail = self._request_parser.feed_data(data)
  File "aiohttp/_http_parser.pyx", line 551, in aiohttp._http_parser.HttpParser.feed_data
aiohttp.http_exceptions.BadStatusLine: 400, message="Bad status line 'Invalid method encountered'"
2022-09-04 18:30:29.212 ERROR (MainThread) [aiohttp.server] Error handling request
Traceback (most recent call last):
  File "/srv/homeassistant/lib/python3.9/site-packages/aiohttp/web_protocol.py", line 334, in data_received
    messages, upgraded, tail = self._request_parser.feed_data(data)
  File "aiohttp/_http_parser.pyx", line 551, in aiohttp._http_parser.HttpParser.feed_data
aiohttp.http_exceptions.BadStatusLine: 400, message="Bad status line 'Invalid method encountered'"
2022-09-04 18:30:29.253 ERROR (MainThread) [aiohttp.server] Error handling request
Traceback (most recent call last):
  File "/srv/homeassistant/lib/python3.9/site-packages/aiohttp/web_protocol.py", line 334, in data_received
    messages, upgraded, tail = self._request_parser.feed_data(data)
  File "aiohttp/_http_parser.pyx", line 551, in aiohttp._http_parser.HttpParser.feed_data
aiohttp.http_exceptions.BadStatusLine: 400, message="Bad status line 'Invalid method encountered'"
2022-09-04 18:30:29.308 ERROR (MainThread) [aiohttp.server] Error handling request
Traceback (most recent call last):
  File "/srv/homeassistant/lib/python3.9/site-packages/aiohttp/web_protocol.py", line 334, in data_received
    messages, upgraded, tail = self._request_parser.feed_data(data)
  File "aiohttp/_http_parser.pyx", line 551, in aiohttp._http_parser.HttpParser.feed_data
aiohttp.http_exceptions.BadStatusLine: 400, message="Bad status line 'Invalid method encountered'"

Has anyone encountered this before when doing a clean install?

Thanks