I use both ArcGIS Pro and ArcGIS online to set up my layers for web maps.
I noticed lately that if I overwrite a web layer on ArcGIS Pro, any map using it will fail to use that layer (and say it can't be found). So I have to go all the way on ArcGIS Online Assistant to fix the JSON of the web map with the right layer URL. For years, the overwrite web layer just replaced the layer, and also replaced the layer on the wem map seamlessly. Is this a deliberate change in the way that layers work now? If yes, is there any workournd? Or this should be an issue, or I maybe had a change in my workflow that I am not aware of?
I was having the same problem until I discovered that I was overwriting the layer with a source Layer ID different to the target web layer's ID. I now check the Layer ID of the target layer and manually change the source layer's ID (if necessary) before overwriting. This has solved the problem for me, but it would be nice if the overwrite web layer tool did a check for inconsistent Layer ID's, alerting the user when they don't match.
Could you please elaborate a little bit more on what you mean by this? If I'm overwriting a layer in ArcGIS Online from a similar feature class in ArcGIS Pro, how is this possible?
Also, be sure to check the Allow assignment.... box in Pro "before" you publish the service. That way, overwriting the web layer will preserve the layer ID's and you won't have this problem.