Chapter 59 of Dragon Ball Super shows Goku continuously attacking Moro with his Ultra Instinct Sign abilities, but the last scene of the chapter reveals that he has a stamina limit for his Ultra Instinct Sign transformation.
Afterimage technique huh ? pic.twitter.com/AJJ0v5yhk0— SUPER クロニクル (@DBSChronicles) April 20, 2020
As Merus, Whis, and Beerus watch the fight from afar, Merus explains that Goku was only able to master using the Sing version of the Ultra Instinct form at will, and not the "true" mastered version of Ultra Instinct during their training period, and Whis said that Sign is supposed to be used as a stepping stone to the mastered "true" version of the form, and thus drains a huge amount of Goku's stamina, so Goku will need to learn how to keep the form active while his energy is being drained.
While Goku has already shown Moro that he can unleash his Ultra Instinct Sign form at will, this chapter proves that the battle is far from over. With all the pressure from fighting someone as powerful as Moro, it's likely that Goku will once again power-up to his Mastered Ultra Instinct form just like how it kicked off in his fight with Jiren at the Tournament of Power. We also haven't seen Vegeta join the battle yet, so don't expect Moro to be taken down in the next few chapters.