Anarchist cave mission (Kouri mission) - getting back in!

I’ve just realised the hostage and escaped the mine but I can’t seem to get back in there to finish off the horde now that I’ve replenished my ammo. And I want to collect all those ears!

The way I got out isn’t reachable to get back in. I can’t seem to jump up anywhere to go into the mine.

Is this the case for everyone or is there another way in? Thanks!