After updating to the latest version of PHP 7.2 we are seeing sporadic errors for a handful errors. We are investigating the problem.
Edit 9:45 Europe/Berlin: We have downgrade PHP to the previous version 7.2.17 and the errors have stopped for now. We are investigating the cause. This happened to about every 1000st request, in what looks a random pattern right now. We hope to find the culprit soon.