Hue integration could not connect to bridge

Hi

Since yesterday, my HA was unable to control my Hue lights. The integration said something like “unable to connect to hub”. And I didn’t changed anything the last month. Restarting HA and the Hue hub → still same problem.

On my android, with the Philips Hue app, I still could control all my lights.

Everything became OK after I upgraded the Hue hub by using the app on my Android.

But I don’t like this. Everything was still working with the Hue app on my android.
Why suddenly, HA does not work anymore with the outdated firmware on the Hub?
Is the Hue integration of HA making a connection to the internet for verifying which firmware I’m using on the hub?