Hi Tim,
it wasn't my intention to botch our song, so sorry for that.
But I think, the main problem is, that we don't use a common audio tool to combine all tracks in a proper way in one audio project. So the easiest way to avoid such unintentional changes is, that every track has the same timeline: Stefans tracks starts exactly after 2 seconds. After this time the song starts. What I've done is to add the 2 seconds to all tracks and, if required, an additional silent part at the beginning of each track, so they all can be overlayed without changings and without using proprietary audio software.
To cut a long story short please send me your single audio track again after you have included the muted part in the correct length at the beginning of your track, so that your part starts at the time you want it to start. Then I'll mix it again.
Best regards!