Are you by chance using the test hand feature? If so, in order for you to test your card effects out, the test hand feature allows you to go into the battle phase rather than having to pass to the opponent, then take the turn back and then enter battle phase.
The only reason why you are required to go into battle phase is because Berserk Gorilla is REQUIRED to attack when it is on the field, which means you must enter the battle phase and attack with it before passing turn. Again, this would only happen on the first turn if you are in the Test hand mode.
Once again, thank you for making a bug report and helping Omega be the best it can be.