After completing the raid on the grove it asks me to talk to Minthara. When I approach her it doesn't give me the option to talk to her so I can't continue the quest

Yup I've got this bug, too. There is supposed to be a sequence when you clear out the courtyard area in the grove (I'm assuming this is when you kill all the tieflings outside the room where the druids are hiding), minthara and company will head to the door. I couldn't get that to trigger last night after several attempts. It seems to be bugged and it locks progression of this quest, sadly.

Yes, I have this issue too. Cleared the whole grove, everyone is dead. Can't speak to her.
Tried pushing her to maybe reset her, and I could to that. She just walks back in place and I cannot click her to start a conversation.

Hope they'll fix this soon, since it completely halts your progress right then and there

After I killed the refugees, she said "come lets kill the druids!" so i just slept instead because I needed to. I came back and couldn't find her, so killed all the druids alone. Then found her back in the cove near the refugee group group behind the stone door. Then she says lets party tonight. So I tried to sleep, nothing. Then had to leave that area, then go sleep and talk to my people, then sleep again.

Basically, doing something that pushes the story forward with companions and restin and stuff might do something for you

I progressed gale's story, freed Volo, rested twice, switched party members, but alas.

Still the same bug. I can right click her, but not talk to her. Didn't even get to her mentioning the party. Punishment for killing all those innocent tieflings perhaps :')

I just checked with the new big patch out, still can't talk to Minthara.

Has anyone found a solution to this?

Same bug here...