It is possible to take damage while you are standing at the edge of soul sand or mud next to lava. This is also a repost of MC-1448 for Minecraft Bedrock.

Steps to Reproduce:

1. Build this structure:
2. Stand at the edge of the soul sand or mud that is right next to lava without falling in.

Expected results:

You should not catch fire if you are standing on the edge of soul sand or mud that is right next to lava.

Observed results:

You will catch fire if you are standing on the edge of soul sand or mud that is right next to lava.