Deepslate blocks hallways in Trial Chambers in worlds created after 1.21

Steps to Reproduce:

1. Find a Trial Chamber
2. You may find a blocked hallway

Expected Result:

It shouldn't be blocked and should lead to somewhere

Bedrock Edition affected info:

Seed: 7306644533854031802

Coords: 70, -35, 201

Preview affected info:

Seed: 7153671743751027767

Coords: 202 -33 836