It's important to note that when you publish or overwrite a layer, what you're doing is setting the default symbology, labeling, scale range, etc. These are the settings visible in an item's Visualization tab in the Portal. Once a layer is brought into a map, however, those same settings can be overridden specific to that map. If the map is updating to the new defaults (which I have seen happen), it's seems to be because the web map has no other settings of its own for the layer. But if I adjust any settings in the map, these take precedent over the layer's defaults, and future overwrites won't impact them anymore. It sounds as if the web maps have a non-default visibility range stored. Thankfully, there is a simple way to deal with this. In AGO Assisstant, go to the web map's JSON and look for the minScale/maxScale items in the operational layers. Delete those lines. That's it! Really! Here's an example: I have a web map with a voting precincts layer in it, and I have a custom visibility scale defined (the image above). The layer itself has its own separate visibility range default. On the web map JSON, I deleted the min/max scale properties. Rather than having no visibility scale, the layer reverts to the default setting. Here's an app that references the app. Despite no visibility scale being defined in the web map's JSON, you can see that at a certain scale, the precincts layer is no longer visible.
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Hey there Nicolas, That is an interesting find! I would recommend logging a tech support ticket which will allow our support staff to investigate the issue and log a defect as appropriate or troubleshoot it. If you already have a ticket open, please let me know what the number is, so that I can keep this thread updated with outcomes.
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