Had a small test app running fine (populated a realm with a few objects, pulled them out again to bind to a ListView, all very simple). Added in the PropertyChanged.Fody nuget and added to the FodyWeavers.xml. After that all objects in the realm appeared to have null values. Removed the nuget and weavers entry, re-built, and everything fine again.
I know that Realm uses Fody to weave all sorts of magic behind the curtain - would you expect it to be upset by using the PropertyChanged weaver as well?