When you place the poppy in the crafting grid, it doesn't present the red dye and then the game idles for a moment and the goes to waiting on server. then it goes back to normal.

This is the same for vanilla crafting grids and other mods like Refined Storage.

I have the same issue. At some point, my server started to freeze after clicking "Move items" in JEI or when I put something in the crafting grid. There is a log attached.
Versions: 8-1.0.21 and 8-1.0.21b
launcher_log.txt