I .....
So my advice is how you should approach it :
- it doesn't matter how you handle the owlbear in the gobbo camp as long as you gain it's trust and is willing to follow you to the camp. You just need to a couple of animal handling checks
- checks are considerably easier if you have Silvanus Blessing buff from the grove and the cleric'd guidance buff active
- after you made this successfully - you get something like the owlbear would follow but is afraid of the gobbos so you have to deal with them one way or another - kill the gobbos in the courtyard but do not (!!!) kill the Gobbo leaders (!!!)
- return to camp and take several long rests to see if the cub eventually appears.
- still chances are that you lose it after celebration party
The Owlbearcub is going away several times from your camp. Its like a Cat, does things and comes back again after some long Rest and maybe you even have to do some short rests before that or/and some fast Travels( but i dont think time is yet implemented besides long and short rests).
What happened at my Camp was when the Cub finally arrived and you allways use a Animal Speaking Potion or have a spell for that:
Owlbearcub has several options then to talk and even some Stat dicerollchecks.
It talks about beeing hurt and you can try to tell him that he should take on smaller enemys. This f.e. makes him leave camp and for some days/long/short rests etc. he will come back with some prey and wants you to eat it.
After that when you successfully ate and Cub will say so that camp is his home. But anyway he will again vanish into wilderness and again for some time at least at my game.