Error authenticating users with minecraft.net

[lokka30]

Hi! I've came across an issue with my Waterfall setup.
My users aren't able to connect, as they get kicked:

Error occurred while contacting login servers, are they down?

(Nope, the login servers aren't down)

On the Lobby server, bungee-cord is true and offline-mode is false.
The lobby server runs paper-33 (latest for 1.15.1) and the Waterfall is at the latest version too.

I tried a lower version of paper, no results.
I tried reinstalling the modules, no results.

Thanks :)

[mikroskeem]

Errors point to DNS error, check your server's DNS configuration.

[lokka30]

solved by electronicboy: 'disable the async dns feature in waterfall.yml'.