If happened, there will be a log about "java.lang.ArrayIndexOutOfBoundsException: Index X out of bounds for length X" or "java.lang.NullPointerException".

The whole log can be like this:

[Netty Server IO #1/ERROR] [net.minecraft.network.Connection/]: Exception caught in connection
io.netty.handler.codec.EncoderException: Failed to encode packet 'clientbound/minecraft:custom_payload'
(Stack information...)
Caused by: java.lang.RuntimeException: Failed encoding custom payload tubesreloaded:sync_tubes_in_chunk: java.lang.ArrayIndexOutOfBoundsException: Index X out of bounds for length X
(Stack information...)
Caused by: java.lang.ArrayIndexOutOfBoundsException: Index X out of bounds for length X
(Stack information...)
[Server thread/INFO] [net.minecraft.server.network.ServerGamePacketListenerImpl/]: (Player name) lost connection: Internal Exception: io.netty.handler.codec.EncoderException: Failed to encode packet 'clientbound/minecraft:custom_payload'

The example is in Minecraft version 1.21.1. However, the problem isn't only in this version.

I haven't been able to reproduce this, can you send the entire crashlog?

I did find a similar bug that was fixed in Tubes Reloaded for 1.21.1 and More Red for 1.21.5

More Red doesn't have any pipe blocks in 1.21.1, if you do find a crash log please reopen a ticket for the correct mod