I see your mistake now.
You are using the terms normal and natural as interchangeable terms.
First you stated it was unnatural but since then you stopped saying unnatural and replaced it with saying it isn't normal.
So if the position you are taking is homosexuality behavior is not normal behavior in the homo sapien species because it occurs at a lesser rate than heterosexuality behavior, then I am inclined to agree with you. In that sense it probably isnt normal.
The question now because, does that make it bad or wrong? Does normal = good and not normal = bad?
In the sense you are using to define normal, something that occurs in the majority, does being normal or not have any real merit? Society has changed throughout history and has experienced many things that were once normal and aren't any more. These changes can be good and bad. The denormalization of something and the subsequent rising in popularity for the opposite can be quite good. Two examples are women's rights and slavery. During the transatlantic slave trade, slavery was the most normal act. Everyone was doing it, literally the rest of the world was participating in slavery (actually North Americas involvement in the slave was pretty low compared to say South Americas involvement)
So we have an act, slavery, that was occurring at a very high frequency throughout civilization. It is safe to say that owning a salve during this time period was considered normal correct? Matter of fact something that would have been not normal would be if someone were to suggest slaves were not inferior creature and were equal to the rest of humanity. A statement like this would have not been normal.
Where am I going with this? This is just an example of why the bandwagon fallacy is a logical fallacy. That just because something is generally accepted as normal it does not make it right and conversely just because something isnt considered normal, it does not make it wrong. You evaluate claims based on the claim itself and not what the popular opinion is of the time.
So I can admit, homosexuality is probably not normal in humans. Now my question to you is what does this mean?