I began making a homebrew race based on the warforged, without purchasing the official race. When I shortly after, wanted to make a new character with my warforged variant, I found that i had the posibility to make a official warforged character. The bug is can be replicted by making a homebrew race based on a official one, then making a new character shortly after.

The Warforged race, as well as all eberron races, are currently in playtest and anyone can use them.

You can't make a homebrew based on a race (or subrace) you don't have access to.