Hi, I have this issue with my server where upon putting in everything inside the brewing stand, once it begins to distill, it kicks me out of the brewing stand GUI and once i right click it, it won’t work. i cant see the arrow going down either. Anyone know a fix? i’m running 1.17.1 paper, do i need to give any other details?

I'm having the same issue too. running 1.17.1 spigot

Upon running the code locally with some extra logging statements. I managed to roughly pinpoint the issue.
During the BukkitRunnable, it runs the update() method on the Brewing stand. When these two lines are commented out, the player is no longer immediately kicked out of the GUI.
However, this either left me with different issues or new issues. One of which is that the player is still kicked out of the GUI when adding OR removing a potion from the brewing stand while it's distilling :p

Finally, I rested this on Bukkut, Spigot and Paper, but this seems to be a bug with Paper.

Whelp... this issue has been fixed after updating to the latest version of Paper.
Have a good day.

Whelp... this issue has been fixed after updating to the latest version of Paper.
Have a good day.

I don't know about the other person, but I'm not currently running Paper-- just plain old Spigot.
Going to hop into my server to triple check everything.

Try getting the latest Spigot version. I tested Spigot earlier today with one of the latest builds.

getting the latest spigot build fixed it, thank you for your help!!