google analytics: the average page load time is 0.00 for page visits> 100 in a week and is higher for p.v.

Some of the pages on my client's website have page views> 100 in a week, although the average page load time is 0.00 seconds

and if PageViews <100 in a week, although the average page time is displayed.

I understand that time metrics are based on 1% of the data collected by default; I also read the Google documentation https://support.google.com/analytics/answer/1205784?topic=1120718&hl=en

But this does not explain why I am getting that data.

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