Sometime between 1 December and 1 January, one of the updates broke the tooltip on the ‘Visits over time’ widget. It now reports ‘0s Avg. generation time’, which is a vast improvement on my normal 0.18s, but the server hasn’t changed, so the issue must be one of the matomo updates that arrived during December. I didn’t notice it in December because it said “0.18s Avg. generation time”, all month, but since the new month started, matomo informs me that all my pages are generated in 0 seconds. I think this is untrue.
The simple avg. generation time report has been replaced by the more complex performance metrics and this number is just still shown so you can access your old data (before the Matomo 4 update).