Minecraft 1.16.3
MinecraftForge 34.1.33
StorageDrawers 1.16.3-8.2.1

Whenever I come close to the drawer this happens.

Turns out that when I disable the [NewDefault+ v1.35] resourcepack and the visual bug is gone.
Maybe it's a conflict?

I confirm also for 1.15.2. As far as I understand it happens with glowing textures

Same problem, but with torches.

It's a problem with emmisive textures in your resource pack and an interaction between Optifine with Storage Drawers. Removing any _e.png textures from whatever resource pack you are using will remove the floating artifacts.