core: TP-Link Kasa switches went "unavailable"

The problem

After upgrading to 2021.02, all my 50 switches are “unavailable” now!

I tried reloading the integration and also restarted home assistant and also core, but it did not work.

Also, I’m unable to reload the integration now. It says “reload will happen after restart”.

What is version of Home Assistant Core has the issue?

2021.2.0

What was the last working version of Home Assistant Core?

2021.1

What type of installation are you running?

Home Assistant OS

Integration causing the issue

TP-Link Kasa Smart

Link to integration documentation on our website

Example YAML snippet

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Anything in the logs that might be useful for us?

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About this issue

Sure…will open a new issue soon.

I had the same problem after upgrading my host OS, turned out to be a firewall issue blocking discovery.