Ok so:
- Gale has been resurrected, but he only thanked me for it.
- I don't usually use tadpole spells (I used it maybe once)

About the approval thing. I checked. Wyll, Shadowheart and Gale (my current team) have the same level average/medium (sorry I'm not playing in English) But I was able to convince Wyll and Shadowheart to open up to me.

The problem here is that... Gale doesn't have any new dialogues and it's been that way for hours of gameplay already. It's like the trigger that fires his latter convos got stuck.