The thing is, people think you have done something wrong when all the fruit sits at the bottom. Like somehow you're a bad baker, when actually Hummingbird even tell you that the fruit sinking is normal - but how is anyone else meant to know that and not think you're just making excuses?
A few suggestions to stop the fruit sinking, if you can't bear explaining to your family/friends/colleagues that the fruit it meant to sink.
Coat the blueberries in flour.
Cook a layer of batter without the berries for a few minutes until the top has just set then mix in the fruit, pour on top and continue cooking.
Cook the batter for a few minutes before drop the fruit from above - the higher you drop it the lower in the cake it will sink.
The other great thing about this recipe was the way Hummingbird recommended to grease the tin. They recommend greasing it then dusting it with flour. It worked a treat and the loaf practically jumped out of the tin. I used one cal spray to grease it - being a spray is so much easier and less messy - then just sprinkle flour around the tin and shake it.