Piwik keeps overwriting website names


I’m using Piwik on an WordPress multisite environment. In the Piwik environment it shows all the different websites, but the problem that it is still overwriting the website names (and doing that wrong).

The tracking itself seems correct, and every site has the correct Site ID. Also the data is coming in correctly at Piwik side, but the names in Piwik are not corresponding with the correct names of the websites. One name is used for several websites.

I already changed the names to the correct ones in the Website manager, but after a day or so, it is wrong again.

What could this be? On what conditions does Piwik decide the Website name (and change it)?