If it isn’t downloading through your browser either, it makes me think that you’re hitting data caps. Because I just tested each of the links you mentioned (ESB Docs, parts 12, 15 and 26) and they are all working fine.
Changing IP addresses doesn’t always fool the mega servers. Try stopping for a day or so, then give it another shot. If you are still having difficulty then, we can troubleshoot some more.
Still doesn’t work. I tried to download this files using other networks (mobile and work) and devices (other laptop and phone) with the same result. No idea what’s going on. Same problem with ROTJ doc part 48…