Website ranks first when spelt incorrectly, but doesn't rank at all when spelt correctly

Hi. About 3 months ago I launched the website www.aworldover.com. It's a travel blog and I chose the domain name 'A World Over' as I wanted something similar to the phrase 'the world over', ie 'the whole world'.

However, when I search 'a world over' as three separate words, I don't appear in any of the serps and, in fact, Google returns a load of results for the phrase 'the world over'.

But when I search 'aworldover' as one word, or when I do an exact match search for 'a world over', my site ranks first. But obviously, if people are searching for my website directly, they are not going to search using either of these ways.

This has me slightly concerned and questioning whether I should change my domain name.

I know that it's early days, and it could just be a matter of waiting until my website has grown in authority to start ranking for 'a world over', but the fact that I'm already ranking first for the misspelt 'aworldover' makes me think that perhaps Google already sees my website for what it thinks is the correct spelling and, therefore, will never rank me for the correct spelling 'a world over'.

So, my question: should I change my domain name, or should I trust that Google will eventually rank me for 'a world over' once my site has gained more authority?

I hope that's a clear explanation - any advice appreciated.

Thanks