Issue report is invalid, please see final edit below.

When a soul lantern is broken or is in the process of breaking, the particles of the regular lantern are shown. This is recreated simply by placing a soul lantern and breaking it, either in survival mode or creative mode. After some testing, it appears that this bug was most recently introduced in 1.20 Pre-Release 1 and has been present in every release version since and possibly every development version.

Edit: Rather confusingly, I am no longer able to reproduce this bug in the current version. I am not sure why this is. I was originally running shaders in the world I first encountered the bug in, however it still occurred even with shaders off and when I reopened the same world in vanilla. Unfortunately I cannot remember if I encountered the bug in a 1.21 world that I did not previously run shaders in. I have not been able to reproduce the bug by running a 1.21 world in shaders and then running it in vanilla, although I can still recreate it in 1.20 versions of the game.

Final edit: After 45 minutes of researching this "bug", I have realised that I had a resource pack installed from Vanilla Tweaks that was causing this issue as a result of it being slightly outdated. From this I have concluded that I should go to bed. Please mark as invalid.