Carbonation will change it a lot. It is a funny thing where if you have too little, it is watery and if you have too much it is thin and fizzy, but just the right amount will make it full.
This is something that commonly is seen with low gravity beers like you made (1.040), and you will see reference to it for english bitters and some other low gravity styles. If you look at the carbonation levels for those beers, they tend to be in the low carbonation category.
If you have one of your other beers, and it is pretty carbonated, try taking a chop stick or something and wisk out some of the carbonation and try it, then do it again and so on with attention to how the mouthfeel presents itself.
Good Luck!