"Failed to login the authentication servers are currently not reachable"

Okay so, my friends are setting up a server, but whenever I try to join, (This is via forge, so we're not using modpacks) this message pops up "Failed to login the authentication servers are currently not reachable. Please try again.", I've looked everywhere for a fix, I've tried editing my host under System32/drivers/etc, I've tried running it as administrator, but nothing has worked. I'm just really confused.

It should also be noted that I'm the only one experiencing this and we're all using to same mods (via zip file), and that I can only (seemingly) play multiplayer if we use a modpack, authorized on aternos.

Curseforge.

Is there a weird interaction between Aternos and Curseforge?