Grease Pencil not effected by lattice for some reason I can not figure out

Hi! I have a Grease pencil object that is deformed by a lattice, everything was working fine until suddenly the lattice does not have an effect anymore - putting on a new lattice modifier does not work, nor does anything else I could come up with. Could this be a bug? I have encountered this behaviour multiple times by now.

Here is the blend file:
GPLattice.blend (1001.9 KB)