Hi @JGVadnais1 ,
This is the current expected behavior for placing the initial extent of the map tour. This will also happen with the default basemap options in a map tour. The extent is calculated off the collection of points added to the tour, and will factor in the desired zoom level if it is set using the Custom initial zoom level dropdown, which you showed in your video. You can also set the zoom level for the individual points throughout the map tour when adding the locations:
I do understand wanting to add a specific extent for that initial zoom. Trying to tweak it a bit with the different initial zoom extents after adding all the expected locations can help a bit. If you need a highly specific extent, you can always use the map block (adding a map to the story instead of a map tour), or use an express map in a sidecar. You can also make a suggestion to allow the custom extent setting in a map tour on the ArcGIS StoryMaps Ideas page, and it may be considered as an addition to the product in the future.
Hope this helps! Let me know if you have any questions on the context above.
--Abby