The regular wall is immune to fire; the reinforced wall is not.

The description reads, Steel-reinforced walls. Stronger than generic walls and extremely resistant to explosive damage. But because of the large amount of metal in the structure, the acid and laser causes increased damage.

The bolded sections are why the reinforced walls should be made immune, in my opinion.

This is not a bug, more a balancing thread. I don't know when Krastor write the wall what is the concept, but if is "metal based" is possible that could be weak to fire, anyway I will refer this to Krastor so we could think about balacing the wall. Thanks for ur feedback