Traveling to Australia from Sweden, problem with given names

So I booked a flight to Melbourne a while ago, and when I booked the tickets for me and my wife I wrote in our names as they are written in the passport. The traveling agency wanted me to specify my "Given Names" and on my old passport, I had my middle name on a separate line which was under "Middle Name", and under Given names was only my first name. So I didn't fill in my middle name in the booking. Worth mentioning is that I have been to Australia before and I did not write my middle name that time either.

So I renewed my passport since it was about to expire and noticed that on my new passport that they removed the "Middle Name" section and instead added my middle name right next to my first name on "Given Names".

Now my issue is that I did not write in my middle name in the booking so I called the traveling agency and briefed them about this and they told me I need to correct this or else I will not be able to fly to Australia. So I called Qatar Airways, the airline we are going with, and asked them about this and they said that it wouldn't be a problem. But I want to be on the safe side.

Does anyone have any experience with this specific situation?