The last MapContrib version has been released today and it contains a security update that changes the Statistics field behavior in the theme settings.
If you were using the Statistics field, replace your code by its image equivalent. Every statistics platform propose that kind of technical solution, Piwik/Matomo included.
We are sorry for the inconvenience but our users safety is one of our priorities.
Thanks to Midgard for warning us about that issue 👋