oh, it gets worse – think i mislead a bit… for post wp 3.5, the storage locations you reference are only for the main site…
so sitewide and main site storage is at wp-content/uploads/sp-resources
but network site storage is at wp-content/uploads/sites/xxx/sp-resources (where xxx is the network site id)
it actually makes sense if you think about it… for main site, wp data store in wp-content/uploads similar to standard wp… for network sites, wp data store in wp-content/uploads/sites/xxx…
for pre wp 3.5, storage for any site in multisite is wp-content/blogs/dir/files/xxx…
post 3.5 makes more sense, but would have been nice if at 3.5, wp moved the data… or, conversely, if we had made the same storage location change (problematic actually) for new sp installs… but not being multisite users, we didnt even know about the change…
so now we have to figure out a way to deal with installs that are post wp 3.5 but pre sp 5.6… like your dev site… installs pre wp 3.5 should be fine… famous last words…
I dont have any solution in mind currently though…