Question

Is it inteded that blocks that have glowstone added, stop being lit when the server restarts?

No, that's not at all intended, it's an unfortunate interaction between Starlight and the way lighting based on data from a blockentity works in 1.20.1 and earlier. This will be fixed properly in 1.20.4 (whenever I actually release that). I will look into the possibility of backporting that fix to 1.20.1, but it might not be feasible to do so. For now the fix is to remove Starlight.

Ah so its Starlight, guess ill uninstall it then, on another note, any idea what this is caused by? And is there a fix? (The obvious difference between a framedglowstoned block and non glowstone

That's caused by how the vanilla game handles light-emitting blocks, specifically the fact that emitting light causes ambient occlusion to be disabled for the respective block. There is unfortunately nothing I can do about this.

That's caused by how the vanilla game handles light-emitting blocks, specifically the fact that emitting light causes ambient occlusion to be disabled for the respective block. There is unfortunately nothing I can do about this.

That's sad. Any tips nonetheless? Maybe a setting or mod that mitigates it a bit?

You could try disabling smooth lighting in the video settings, but that will of course make other things look worse. Other than that I currently have nothing for you unfortunately

Aww, thats a shame, but thanks a lot for your time anyway :) and thanks for keeping the mod active!

After some more digging, I've found a very simple solution to light-emitting blocks being very obvious next to "normal" blocks.