Timer triggered twice in amp-analytics

I would like to trigger an analytics event after the user has spent 10 seconds on the page. This is the code I'm using

> "pageTimer": {
>       "on": "timer",
>       "timerSpec": {
>         "interval": 10,
>         "maxTimerLength": 9.99
>       },
>       "request": "event",
>       "vars": {
>         "eventCategory": "Profitable Engagement",
>         "eventAction": "more than 10s"
>       }
>     }

The problem is, that with this code 2 events are fired: one on page load, and one after 10 seconds.

Is there a way to prevent this behavior, and fire only 1 event?

Live example: https://www.guidallascelta.it/tecnologia/computer/i-migliori-software-per-il-recupero-dati-da-hard-disk-e-non-solo/amp/

Also on the AMP by example site you can see the same behavior: https://ampbyexample.com/components/amp-analytics/#timer

As soon as you load the page, the timer count is set to 1 instead of 0. Then it increases every 10 seconds up to 60.

Thanks!

Use immediate false

The timer will trigger immediately (by default, can be unset) and then at a specified interval thereafter, immediate trigger timer immediately or not. Boolean, defaults to true

"pageTimer": {
       "on": "timer",
       "timerSpec": {
         "interval": 10,
         "maxTimerLength": 9.99,
         "immediate":false
       },
       "request": "event",
       "vars": {
         "eventCategory": "Profitable Engagement",
         "eventAction": "more than 10s"
       }
     }