Polygon Layers are incorrectly offset from basemap / "jump" location until hit zoom or home button or click for pop-up

[ab-ti]

Hello all,

I am experiencing a frustrating issue where my polygons in a Story Map Series (tabbed) are incorrectly displaying their location on first render.

The layers often (but not always) appear offset from what should be their correct position / projection; however, when you click on the home button, a zoom button, or alternatively you click on on the feature to trigger a pop-up it "snaps" to correct position. This occurs both on initial tab loading, as well as if data is being displayed via a story map action.

I am not sure what is causing this as everything is in the same projection.

I have double checked all the included data, I have re-published and re-projected the data to ensure it is correct as well. This is happening across multiple data sources.

Edit: I would also add that this occurs regardless of whether I select a tab to inherit the extent previous extent, whether I use default extent of web map being called, or whether I set a custom extent to zoom to via the story map action.

Technical details:

1. Layers are self-hosted as MapServer services
2. Basemap tiles and reference layer are self-hosted to customize reference style and add one custom scale extent
3. All published layers and basemap (and .mxd data frames) are in Web Mercator Auxiliary Sphere (EPSG 3857)

Some example photos:
On first display, or when click story map action link to display data

Once click on map it snaps to correct display

Does anyone have suggestions or advice in terms of how to correct my setup? Is this potentially a known issue instead?

Thanks!