Cannot add web scene to sidecar or as standalone widget

[qpoterek]

Why, hello there! ‌🙂‌

Being part of a large consortium, we are two companies regularly generating Story Maps on ArcGIS Online to cover emergencies worldwide, leveraging most of the available widgets. For a week now, we have both been encountering issues with our large collection of web scenes (3D), up to more than 2 years old. It is quite a peculiar set of issues...

1. When trying to add one of our web scenes to a sidecar, the "Save" button is greyed out. Up to last February, they used to contain only feature layers. Due to new specifications and complex symbology, we have switched to map tiles instead. Both asset types trigger the same issue, even when fully loaded in the viewer and waiting for up to an hour for good measure.
2. When trying to add a web scene from ESRI's public repository or Living Atlas, the same issue arises, but not always. This used to not be the case before last week.
3. I initially thought the issue might stem from potential recent changes to Story Maps. As a result, I recreated our base story from scratch, step by step, and adding a Map and Sidecar widget every time, before saving, checking the published story, and reverting to the prior state, to proceed with the next step. No problem with basic text or the timeline, but for some reason, inserting a URL triggers the behaviour. Remove the URL and you are good to go again. Add a table, and you are in for trouble.
4. Out of curiosity, I tested switching from our custom theme to any ESRI standard theme, to no avail.
5. Since it seemed to work on an empty or close-to-empty Story Map, I tried to take one of ours that was already populated, and by adding the sidecar right at the top, below the cover, it is possible to insert a web scene, before moving the widget down to its proper position. However, it is then no longer possible to add a new slide (which we do up to several dozens of times in a single Story Map in only a few days), even when moving the sidecar back to the top temporarily. At each update, we have to recreate the sidecar from scratch at the top and move in down, which is not sustainable under our constraints. Moreover, the legend might not appear at all, even though the option is enabled.
6. This issue applies to both the Map and Sidecar widgets.
7. There is no issue whatsoever with web maps (2D), where the "Save" button is not greyed out and the legend systematically appears.
8. I tested it on browsers based on all mainstream rendering engines (gecko, chrome, webkit and webkitgtk), with no success whatsoever.
9. I have tried playing with Firefox and Edge's developer tools, adding and removing bits and pieces of CSS and JS that could trigger the issue, and monitoring resources and network, but no success either.

Greyed out save button for scene in sidecar

Same issue with a scene containing only a basemap

Web map teasing us by working perfectly in the sidecar

Likewise, I have had colleagues from our partner company perform similar tests, resulting in the exact same outcome. Even though there is a pattern, I have no idea how to fix this nor how to narrow down what the actual issue could be. Does anybody here have a clue as to what is happening? ‌😓‌

If you are interested in trying it out for yourself, here is a sample of different scenes:

EMSR807 AOI01 Cumulative (from last week): https://www.arcgis.com/home/webscene/viewer.html?webscene=5943aae1d09c471ea22666ce97ac2d6c 
EMSR798 Latest situation (recent): https://www.arcgis.com/home/webscene/viewer.html?webscene=e00803bbe5c444eeafc5e064c6c094d8 
EMSR785 AOI01 Cumulative (before the switch to map tiles): https://www.arcgis.com/home/webscene/viewer.html?webscene=388a3a477b3043e2aea779fe8ed68d09 

And here is an example of a Story Map where the trick described in #5 worked (the legend being hidden even though toggled in the configuration options of the sidecar): https://storymaps.arcgis.com/stories/5f04d88c47a344ec99ca25f18a023e0e 

Thank you and have a nice day!

[OwenGeo]

@qpoterek - I'm sorry you are having issue adding web scenes. We tested the scenes you provided and cannot reproduce the issue you described (the one with id e00803bbe5c444eeafc5e064c6c094d8 does not appear to be shared publicly, so we couldn't test that one). Below, are screenshots showing one of the scenes with an enabled Save button and the same scene placed successfully in a story. I also tested with about a dozen scenes from the Living Atlas and was unable to reproduce the issue.

I would recommend that you please contact Esri Tech Support so they can better help troubleshoot since the issue appears to be something related to your computers, network environment, or account.