PageTitle transitions bug

we track visitors in multiple sites/accounts with our matomo installation.
For one of our websites we have a “bug” in the section Behaviour -> Page titles. When I click on “transitions” at any of the page titles, it will always show the same information, no matter which page I select. And the numbers are completely wrong, e.g. 20 incoming and 7000 outgoing.

Strangly this does not occur at any of the other sites/accounts in our installation. Any ideas, why this is happening?

I searched the forum for reports on this but couldn’t find anything. Apologies if this has been mentioned already.