Im using Kdenlive 22.12.3, on Ubuntu Gnome...and I'm not sure how to attach a screenshot...

I can bring each MP4 file down to a timeline individually (it splits into vid/aud as it should), but if I try to add a second, it will only allow it to be added to a different timeline, not the same one,which layers instead of linking them when I render it. Im guessing it has to do with the fact that the audio clip that shows up with each is longer than the video for each...though there are no sync problems...

I checked the manual for cutting and editing and the timeline section to no avail, but did see that my "longer audio file size" appeared normal in egs given, though I was told they should be the same size, which makes sense and logically should solve the problem. How do I check the zoom factor ...which doesn't seem possible to "accidentally" change, and make sure there's enough space on the timeline? One file is half hour long, the other 10 min. Is there some kind of tutorial where I can watch someone merge two MP4 files?