wp-cron behaviour when there are multiple queued tasks

Ive experimenting with using a server side cron to execute wp-cron instead of WordPress, as suggested by countless articles.

What I don’t quite understand is how wp-cron is supposed to deal with multiple queued tasks. I’ve been using the WPCrontrol plugin to analyse the crons and noticed that when there are several tasks queued up to run, only the first gets executed when the server cron hits. Is this normal behaviour for wp-cron?

So, for example, if I have 3 tasks scheduled to run every hour, and the server hits wp-cron.php every hour, the result is each of the tasks only execute every 3 hours as they are constantly queued behind each other.

I’ve also tried disabling the automated cron completely, and triggering the cron manually by visiting /wp-cron.php directly using my browser, but the results are the same; only one task ever gets run.

Can anybody clarify how wp-cron execution is supposed to deal with multiple queued tasks? Thanks.