How to get this quest completed.
1. Make sure it's active in the Journal
2. Locate the lost Druffalo
3. Toggle run/Walk so that your character will WALK (that is not bound by default so, you need to bind it to a key in settings- key bindings before starting the quest. I use the / key.)
4. Walk all the way back to the pen the Druffalo belongs in. You can cross water but do not jump, do not run, do not go through your Inquisition Camp. (you do not need to click on the druffalo or interact with it, just walk and it will follow.)
YYes it is possible to walk the entire way without jumping up or down and, without going through your camp and, it works perfectly that way, no stuck druffalo. If you have to jump, druffalo will get stuck and, they do not enter camp so, you've got to avoid those things. Walking lets it stay close to you so that it walks where you do, avoiding rocks that would get it stuck.