Teeny Strawberries?

This is my first season with strawberries. I choose 4 everbearing plants - I think they're "ozark". They're planted in a large container and are out in the backyard in full sun.

The plants look great and they're producing strawberries. But, the strawberries are super duper small. Like the size of a garbanzo bean.

We have been getting loads of rain. But, that's the only thing that seems unusual.

What is the cause of the small strawberries? What can I do to improve them?

thanks!