We recently upgraded our portal from 10.8.1 to 11.1. I went through and rebuilt the web maps we previously made in map viewer beta 10.8.1 in the new map viewer in hopes that this would make the field maps form more stable. However after creating my web map all the layer references I had to the rest urls changed to point to the item id for the layer instead. This makes it quite unstable in case the portal item becomes corrupted or we want to migrate to our QA or PROD environment we cannot simply clone or copy the map since it no longer references the rest ulrs for the service. What is the best practice for field maps? We would ideally only have to create the web map in our lower environment, design the form, then be able to migrate that map and form to QA and PROD. Instead of manually maintaining 3 versions.
We have had some luck swapping these out using AGOL Assistant that lets you edit the JSON.
https://ago-assistant.esri.com/
Hope that helps
Are you swapping the item IDs for the layers back to the service url?