I have a mole just under my left jaw. I could post a picture and tell you which version of Vegas I'm running on which version of Windows, but I prefer to make you ask me twenty questions.
I can't see it well on my iPhone but I still believe you have some track motion enabled. I do see that two of your tracks must have some animation in it, the key track expander is visible in the track header.
General Complete name : C:\Users\Eier\Videos\League of Legends\Kog'Maw Penta.mp4 Format : MPEG-4 Format profile : Base Media / Version 2 Codec ID : mp42 (mp41/isom) File size : 212 MiB Duration : 39 s 84 ms Overall bit rate : 45.5 Mb/s Recorded date : 2017 Encoded date : UTC 2017-04-22 11:54:41 Tagged date : UTC 2017-04-22 11:54:41
Video ID : 1 Format : AVC Format/Info : Advanced Video Codec Format profile : High@L4.2 Format settings, CABAC : Yes Format settings, ReFrames : 1 frame Format settings, GOP : M=1, N=30 Codec ID : avc1 Codec ID/Info : Advanced Video Coding Duration : 39 s 84 ms Source duration : 39 s 84 ms Bit rate : 45.3 Mb/s Width : 1 920 pixels Height : 1 080 pixels Display aspect ratio : 16:9 Frame rate mode : Variable Frame rate : 60.000 FPS Minimum frame rate : 59.230 FPS Maximum frame rate : 60.790 FPS Standard : PAL Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.364 Stream size : 211 MiB (100%) Source stream size : 211 MiB (100%) Encoded date : UTC 2017-04-22 11:54:41 Tagged date : UTC 2017-04-22 11:54:41 Color range : Limited Color primaries : BT.601 NTSC Transfer characteristics : BT.470 System M Matrix coefficients : BT.601 mdhd_Duration : 39084
Audio ID : 2 Format : AAC Format/Info : Advanced Audio Codec Format profile : LC Codec ID : 40 Duration : 38 s 906 ms Source duration : 38 s 891 ms Bit rate mode : Constant Bit rate : 192 kb/s Channel(s) : 2 channels Channel positions : Front: L R Sampling rate : 48.0 kHz Frame rate : 46.875 FPS (1024 spf) Compression mode : Lossy Stream size : 927 KiB (0%) Source stream size : 927 KiB (0%) Encoded date : UTC 2017-04-22 11:54:41 Tagged date : UTC 2017-04-22 11:54:41 mdhd_Duration : 38906
There seems to be track motion on track 1 and the composition mode might be set to multiply which could cause the shift; it's actually a cut if I am right. Mute track 1 and see if it's still there.
I don't understand why it did not go away when you muted track 3. Anyhow, changing the compositing mode will change how your video looks over the entire length of the video/timeline, that's just how it works.