Not sure this is working for me, unless im missing something???
I have a datapack on my server that has fast leaf decay, which I presumed may be interfering, however, same issue in SP without this datapack.

I've removed all mods apart from latest fabricapi and this mod also removed all resource packs
Any pointers I could be looking for that may be causing the interference
MC1.17.1

Screenie was taken with mods, couldnt be bothered to take another :)
same effect regardless

It's working, but it will only look like the OptiFine smart leaves on fancy graphics.
It also improves FPS on fast graphics, it will just have no visual impact.