Me and a friend put together a modpack for private use on his server. It's a 1.15.2 server and has been using 1.12.14. As I started on Astral Sorcery for the first time, I found that on top of all the broken textures because of Optifine, Starlight Transmutation was almost completely broken. I didn't notice it immediately because, ironically, the only transmutation that works is that for the Crafting Table.

After a fair bit of testing, I just tried starting a fresh game with nothing but observerlib-1.15.2-1.3.2, curios-FORGE-1.15.2-2.0.2.6 and astralsorcery-1.15.2-1.12.14, started a new world, located a Shrine and tried to Transmute, but it didn't work. Have also tried with 1.12.13 to see if that was the issue but the problem remains.

I didn't find anyone else discussing it, which I found odd so I just assumed it was something on our side at first. Now I have no clue. As the screenshot shows, the particle effect isn't happening. The screenshot just shows Iron Ore, but I've tried the other recipes I found in JEI and the crystals only seem to recognize Crafting Tables.

Hope you have a good day!

Remove the roof of the shrine. This is the kind of thing that should go to the Discord for assistance, btw.

Oh. Sorry for being an idiot.

The initial auto-linking feature only works for the crafting table -> altar conversion for collector crystals spawned in structures.
Everything else needs to be manually linked later in the mod.