Using ItemStages 1.12.2-2.0.49 with JEI 4.15.0.291 on Forge 14.23.5.2847.

When using ItemsStages serious, consistent JEI desyncs can occur.

In detail: if I hit the + button on JEI to auto-insert items into any crafting grid they are inserted only on the server but not on the client, which not only makes further crafting impossible until the GUI is closed, but also causes heavy inventory desync issues. Sometimes just looking up a recipe (so without hitting +) is causing a desync and makes the crafting table unusable until the GUI is closed. I can't see a pattern here, but the issues happen very consistently, rendering JEI unusable.

This happens in singleplayer and LAN games. Switching between that sometimes cures the desync for a while.

Note: mezz/JustEnoughItems#1808

Also the issue appeared while editing game stages, the problem persists even when ItemStages and Zenstages are disabled. The issue therefore obviously lies somewhere else.