Matomo works - but doesn't record any trafic

I’m trying to move my Matomo instance from an oldfashioned server to Kubernetes. I’ve tried to follow the examples at the matomo-org/docker site at Github.

Basically, everything works: I have two URLs - matomo.<domain>.<tld> and piwik.<domain>.<tld> encrypted using SSL, and I can reach the two sites from the outside world. But the setup doesn’t register any new traffic.

I have three pods/containers running in Kubernetes: A MariaDB using the stock image, the Matomo FPM image and an Nginx frontend. I have backed up the database from the old system and restored it onto the new database. I can access and log in to Matomo, and all my old data is there.

But no new traffic is recorded. I’m not sure how to troubleshoot the Matomo FCGI app, but I can see from the logs that traffic enters Nginx properly - the Nginx log shows an entry for each visit to my medium traffic site.

Any ideas about how to troubleshoot this issue?

Regards,
Lars