core: Logitech Harmony Hub YAML config no longer working 0.108.0b0

The problem

Since upgrading to Home Assistant 0.108.0b0 it broke my Logitech Harmony Hub integration, which I had configured via YAML. According to the docs I have a valid config, but integration is not loading (even after a restart).

Environment

• Home Assistant Core release with the issue: 0.108.0b0
• Last working Home Assistant Core release (if known): 0.107.7
• Operating environment (Home Assistant/Supervised/Docker/venv): Supervised
• Integration causing this issue: Logitech Harmony Hub
• Link to integration documentation on our website: https://rc.home-assistant.io/integrations/harmony/

Problem-relevant configuration.yaml

This is my existing YAML config - as far as I can tell from both the rc release notes and rc docs, this is still supposed to be valid?

remote:
  - platform: harmony
    name: Sean Room
    host: 192.168.86.34
    activity: TV

  - platform: harmony
    name: Living Room
    host: 192.168.86.30
    activity: Watch TV

  - platform: harmony
    name: Bedroom Hub
    host: 192.168.86.25
    activity: Watch TV

Traceback/Error logs

Log Details (ERROR)
Logger: aioharmony.hubconnector
Source: __main__.py:342
First occurred: April 1, 2020, 7:44:45 PM (6 occurrences)
Last logged: April 1, 2020, 7:44:45 PM

192.168.86.25: Unable to retrieve HUB id
192.168.86.30: Exception on post: Connection timeout to host http://192.168.86.30:8088/
192.168.86.30: Unable to retrieve HUB id
192.168.86.34: Exception on post: Connection timeout to host http://192.168.86.34:8088/
192.168.86.34: Unable to retrieve HUB id

When I visit those URLs seen in above logs via Google Chrome browser, it immediately brings me to HTTP ERROR 401

Additional information

My three Harmony hubs show up in Integrations -> Discovery, so they are being recognized and it’s offering me to set them up via the UI. But my existing YAML config is no longer working.