General question on fit in the apron.

When I tried on a kilt for the first time, I tried on a 38 & a 40. It didn't matter which size it was, I ran into the same problem of seeing my junk in the front because the apron didn't lay flat. Seemed tight in the front. Is this an issue of how tight I buckled one of the buckles and would be alleviated with adjusting them or is this a fit issue from my body type/shape and will be alleviated with a properly measured and custom made kilt?

Any input on this would be helpful.

Thanks,
Matt