See, I have the opposite problem, Gale hitting on me ASAP. Basically just keep him in your party and play as a mostly good character, and you’ll gain his approval quickly. He also has a soft spot for mischievous kids, so helping out the tiefling kids will gain approval from him.
Also take regular long rests. Like a LOT of them. (I take 4-5 before even getting to the grove, I do Withers first.) I wouldn’t say you should spam them, because there’s no point in long resting if nothing is coming up. But, do it very regularly and trust me, that little exclamation point will pop up over his head and he’ll want to show you how to cast magic and make out lol. It sounds like you missed his early act 1 romance scene (conjuring the Weave) and that’s why the rest of it never happened.
