Definitely not my intention. Here is the properties of the source file
Gyazo - ac1b8e296786b878ba51269add248d5d.png
Go to File > New > Sequence and create a new, empty sequence. It doesn't matter what those settings are.
Once the new, empty sequence is created, drag one of your source clips into it. You should be prompted by Premiere to match the sequence to the source clip. Click the button to change the sequence settings to match the source clip.
Delete the clip you used to set the settings so that the sequence is empty again.
Return to the sequence where you did your 8 minutes of editing, and click anywhere in the timeline. The Control (Command) + A to select all the clips in the timeline. Once elected, copy them by typing Control (Command) + C.
Switch back to the empty sequence you just created, click in it and then paste the copied clips there.
If the clips do not look correct in the new sequence - either too small or distorted - then select all the clips in the timeline, and once selected, right click on any one of the selected clips and from the drop down menu choose Remove Attributes. When the Remove Attributes pane opens, make sure Motion is checked and click OK.
You should be good to export now.
MtD