I am running Complementary Shaders and I assume that you tried to inregrate some shaders functionality to the buoy to light them up in the night and turn them off during the day. Great idea, but I think it is implemented backwards, because it turns off during the night and lights up during the day.

Playing on the new HA update

We actually have not implemented that at all, theyre meant to stay lit all the time, and this is probably just a shader bug. I dont think we can fix it in our end because we did the buoys the same way we did every other glowing texture in the mod and so it should work fine

That's odd :/

Every glowing fish texture works without any issues. I guess I will have to Ignore it then.

Im going to close this issue for now but if we ever find a fix for it on our end (unlikely so no promises) I'll reopen it and let you know it's fixed

It seems Iris doesn't know how handle light interaction with the glowmask, you can fix it by making a resourcepack that replaces assets/hybrid-aquatic/textures/block/buoy_glowmask.png with an "empty" one:

New texture:

(glowmask contains 4 pixels that are hidden under the lamp post, it's necessary since making a whole glowmask empty causes a crash)

Screenshot with Bliss shader: