The grey beams emitted towards the Ender dragon do not display once ray tracing is turned on.

Steps to Produce:
1. Open a ray-tracing capable world or create and enter a world with a ray tracing resource pack and turn ray tracing on. (You can use any texture pack that allows you to turn ray tracing on, I've attached an empty ray tracing resource pack which is ideal for testing bugs)

2. Spawn a dragon near an End crystal, you can use a repeating command block to ensure dragon remains in a single spot, then spawn an end crystal near it.

3. Turn ray tracing on and off while closely observing ender dragon beams.

Observed Results:
Ender dragon beams disappear as soon as ray tracing is turned on.

Expected Results: 
Ender dragon beams should display with ray tracing in a similar way as vanilla Minecraft.

Additional Notes:
Material for the beam seems incompatible with RTX graphics mode.