Players can't join, cause "sub server is offline" (more in explanation)

[Mithranduil]

Bungeecord version

git:BungeeCord-Bootstrap:1.20-R0.2-SNAPSHOP:9e83ee6:17

Server version

Paper-176 MC:1.20.1

Client version

1.20.1

Bungeecord plugins

AdvancedBan, AntiBot, BungeeTabListPlus, CraftingStore, Geyser-Bungeecord, Luckperms-Bungee, Pl-Hide-Pro, Plan-5.5. Analytics, SCAutoBroadcaster, SlashServer, floodgate-bungee, minimotd-universal, nuvotifier, protocolize-bungeecord

The bug

Due to an unregistered bug, players can sporadically no longer join a sub server.
We use multiple sub servers that can be joined through a hub/lobby server.
4 of the 5 sub servers, including the hub can be entered normally, the forwarding and /send works normally.

The one sub server, no great differences from the others, no plugins that are not also installed elsewhere, but cannot be entered.
The error message is the following from the messages.yml of "server_went_down". The sub server is supposed to be down.
The surprising thing is:
There are already players on it. There are already 30 players on the server, suddenly no new players can join because of the error message. Then the sub server has to be restarted to fix the problem.
Most of the time it works again after a few minutes, so you just have to wait and see.

As mentioned at the beginning, there are no logs about this, except for the message that the player who tried to join is disconnected again.

Log output (links)

there arent any log files, searched the startup logs but there arent issues.
also there arent issues or errors when the players join the server

Checking

• I am using BungeeCord and not a fork. Issues with forks should not be reported here.
• I think this is not an issue with a bungeecord plugin.
• I have not read these checkboxes and therefore I just ticked them all.
• This is not a question or plugin creation help request.

[Janmm14]

Did you set connection-throttle: -1 in bukkit.yml?

(HOWEVER DO NOT set it to -1 in bungee's config, thats a huge DoS risk and completely unrelated to this problem!)

[Mithranduil]

Did you set connection-throttle: -1 in bukkit.yml?

(HOWEVER DO NOT set it to -1 in bungee's config, thats a huge DoS risk and completely unrelated to this problem!)

currently set to default to 4000.
thats the setting for alle the other servers too

[Outfluencer]

You can set it in bungeecord to -1 if you have connection limit with iptables or something else, with iptables it should also be more efficient

[Janmm14]

Did you set connection-throttle: -1 in bukkit.yml?
(HOWEVER DO NOT set it to -1 in bungee's config, thats a huge DoS risk and completely unrelated to this problem!)

currently set to default to 4000. thats the setting for alle the other servers too

You need to set it to -1 for every bukkit/spigot/paper/etc server behind your bungeecord.

This is written for example as first thing in the Post-Installation section here: https://www.spigotmc.org/wiki/bungeecord-installation/#post-installation

Please also read the rest of that section, maybe your spigot servers are not yet secured from outside connections.

[Mithranduil]

Did you set connection-throttle: -1 in bukkit.yml?
(HOWEVER DO NOT set it to -1 in bungee's config, thats a huge DoS risk and completely unrelated to this problem!)

currently set to default to 4000. thats the setting for alle the other servers too

You need to set it to -1 for every bukkit/spigot/paper/etc server behind your bungeecord.

This is written for example as first thing in the Post-Installation section here: https://www.spigotmc.org/wiki/bungeecord-installation/#post-installation

Please also read the rest of that section, maybe your spigot servers are not yet secured from outside connections.

hey, im reading the complete installation part and set the throttle to -1, etc.
but today, at 9 pm the same issue is happen again, the sub server server is online, some players are online but new players cant join

any ideas

[Janmm14]

I do not think there is a problem inside bungeecord. You do have some invasive bungeecord plugins (geyser, protocolize, tablist). I suggest you try without these, or if not possible to seek for further help using spigotmc.org forums (as I don't think there is a problem inside bungee).

If you or a dev of your server is capable, add t.printStackTrace(); statement to log the exception here. This might help to find the cause of the problem when you post that in the spigotmc.org thread.