This bug report is a parity issue with Java.

Summary:

Roots can be destroyed by fire in the bedrock version. In the Java version, they don't even set on fire MC-176491.

Steps to Reproduce:

1. Take crimson roots or warped roots.
2. Place them on top of lava or set them on fire with a flint.

Observed Results:

Roots will ignite and burn out.

Expected Results:

The roots will not ignite and burn.