core: Disabled input_boolean cannot be re-enabled without restarting Home Assistant.

The problem

An input_boolean can be conveniently disabled but it cannot be re-enabled unless you restart Home Assistant.

Environment

• Home Assistant Core release with the issue: 2020.12.2
• Last working Home Assistant Core release (if known): probably never
• Operating environment (OS/Container/Supervised/Core): OS
• Integration causing this issue: input_boolean
• Link to integration documentation on our website: https://www.home-assistant.io/integrations/input_boolean/

Problem-relevant configuration.yaml

The input_boolean is created via Configuration > Helpers.

Traceback/Error logs

No errors reported in Logs.

Additional information

• Create an input_boolean using Configuration > Helpers.

• Go to Configuration > Entities view and disable the newly-created input_boolean, then re-enable it.

• A popup appears indicating it will take 30 seconds for the entity to be enabled.

• One minute later it still indicates Unavailable. Waiting longer doesn’t correct it.

• Refreshing the web page doesn’t correct it either; it continues to report Unavailable.

• Executing ‘Reload Input Booleans’ also fails to correct it.

• In my tests, the input_boolean was used in an Entities card and it was missing from the card.

• Restart Home Assistant and the input_boolean is finally re-enabled.