Why does conbee ii stick realy on phoscon.de to be active on internet

yesterday after about 4 years of use my conbee ii stick stopped working on homeassistant, i noticed when trying to get onto phoscon.de to see what was going on that the website was down, funnily enough when it come back up my conbee ii started to work again.

why is this stick relying on phoscon.de to be active on the internet in order for it to work on a locally hosted server running homeassistant???

anyone care to shed any light on this please