Author.php only shows the 5 most recent posts!

Hi all,
I’m having a problem I don’t seem to be able to solve. I have a specific author page for each author which shows all of the authors posts. However, it only shows the 5 most recent posts … and I can’t see where that criteria can be changed to show all of the authors posts!

https://www.vefritid.is/index.php/hofundar/
Here is a list of all my authors.. only one of them has over 5 posts – Gretar Halldor Gunnarsson. As you can see he has 7 posts (it’s in Icelandic, I know, but the numbers are the same!)

https://www.vefritid.is/index.php/greinasafn/author/gretar/
When you click Gretar’s name you get this page, with all of his posts… or what should be all of his posts. It only shows the 5 most recent ones. I have creating posts for other authors so they have over 5 posts as well, and the author.php page also cuts the oldest posts away, so this is not a problem specific to Gretar.

Can anyone help me with this and inform me of what I’m doing wrong… or where I can change this setting?

Below is the code for the author.php page:

[code snipped. Use a pastebin like https://wordpress.pastebin.ca/ and post back a link if the code is necessary]