Hi Chris,
It’s highly unlikely you’ll need to modify the Fetch instances to achieve what you want here.
It seems your code has changed quite a bit since the last time you shared it. For example, there is no occurrence of (r, o) -> at all in the code you have shared so far. This makes helping you based on debug messages really hard.
Is there any chance you could put up your code somewhere we can access, say GitHub? Alternatively, could you share the parts that generate errors in their current form? It’s difficult to guess what’s going wrong in the new version of your code while looking at older versions.