Minecraft io.netty.channel.AbstractChannel $ AnnotetedConnectException: Connection refused: no further information: -ERROR fix?

Yesterday I played normally on the Minecraft 21w06a Snapshot Server, from my friends and me. Everything was fine until I placed several beds in the Nether, hid behind a block, and right-clicked. Then it lagged briefly and the error message from Java came. Something with Java.lang, I can't remember exactly. At first I thought I had crashed the server with it, but that would not have been possible because I had been looking for Netherite with Betten all the time beforehand. Yes, and now whenever I want to join, the error message appears: io.netty.channel.AbstractChannel $ AnnotetedConnectException: Connection refused: no further information:. I looked for solutions on the internet and found out that it only comes when the server is overloaded or has run out and only the admin can solve it.
So I wanted to ask is it true, or does it have something to do with my connection, because I can still join other servers (mc.hypixel.net, Gommehd.net, …)

It's up to the server. The best thing to do is to restart the server. But be careful not to kill him. Otherwise part of your progress is gone.

Ok, I'll write that to the admin, thank you

All right, server restarted and fixed, thank you