Yes IIRC Samsung S7 (if not all samsung phones?) prohibits apps from writing to the sd card (part of samsung phone security model), or at least to directories that the apps do not "own".
1) Technically, you can probably try to do the samsung "move whole app to sd card" function, but unfortunately, that option is not available for every kind of third-party app (may not even be available for the gopro app either).
2) Samsung phones, likewise, also probably disable "adaptable storage" (i.e., treating your sd card like an mere expansion of the true "internal storage"), a feature already introduced simply in Android 6.0 OS itself. Probably due to samsung phone security model too (unless you root it / void warranty?).
Well, let's see if any "dev comments" about this ever make it into this thread ; )
