I can confirm: charge attacks ignored this case. But I added now a check so that units only charge on a target if it can be reached over a line of (for this unit) walkable tiles.

I found now cases where it happens, caused by charge attacks.
So they charge to a unit on lava and get burned.
But I did not saw them just "walking" into lava.

@Terrakul it is not exactly easy to reproduce.
In my test case they do not follow the Archon on to the lava and stick back and thus do not get burned.
Can you confirm the problem is still present?
Could you record a video?

@Scott Richmond Juggernauts can walk on lava and are intented to do so regularily.

The dwarf on the other hand, should not do that. But I guess he was either pushed by the other units or, he did a charge attack.I need to check if charge attacks actually take this case into account.