The sculk blocks such as sculk, sculk catalyst, sculk sensor, and sculk shrieker don't drop XPs when being blown up by an explosion such as TNT. Some of the blocks (sculk, sculk catalyst and sculk shrieker) can currently drop XPs upon explosion on Bedrock Edition, which creates a parity issue.
How to Reproduce
1. Place a layer of sculk with commands.
2. Set off a TNT in the middle.
3. Repeat the same steps with other sculk blocks.
No XPs dropped when destroyed by an explosion.