Friend can't join aternos servers

My friends and I were joining my Aternos server, but one of them couldn't join and it kept showing up "io.netty.channel.abstractchannel$annotatedconnectexception: timed out"

I tried to make another server to see if they could join that one, but the same message happened. They can still join other servers not from Aternos.

Nope. I tried DynIP, same result, and the connection attempt doesn't show up in the server console.

Yes I can.

She just can't join any server that is from Aternos.

She is able to search it up on a browser.

Problem still hasn't been resolved :C