I have my Project set up in 4.10 and I can use the Grain film perfectly fine.
when 4.11 came out then the grain film still worked but I had to delete it, so when I added it back I enabled the Film grain and set the intensity and jitter 0.5 and got no results.
I had the same problem, but when going from 11 to 12.
switching to 4.16 fixed it for me.