Flame Surge interaction with RF bugged?

I was using Flame Surge with RF and noticed that Flame Surge will create burning ground while the enemy is under the burning effect of Righteous Fire. Also, when the burning effect of Righteous Fire is removed, the burning ground disappears. I have nothing creating an ignite on the enemy. Link below is a short clip of this effect.

https://youtu.be/krGpxvy7x2s