Ok!
So after a lengthy discussion with Bluehost we “resolved” the problem.
I was using the plugin WP Super Cache. I cleared all the cache through the plugin and on my browser. I then deactivated the plugin and cleared the cache once again.
No matter what I did the site health still read needs improvement because of the cache.
Bluehost ran some tests and said the cache wasn’t affecting my site so despite the site health reading “needs improvement” there was nothing wrong.
So the site health hasn’t changed. But the answer was it doesn’t matter? Because the site wasn’t being affected.
Not sure if this will be a problem in the future however. So we shall see!