Playing as Sister of the Thorn on Festering Ground just now, a Chaos Spawn spawns by the section with vines, after 2nd grimoire and before 3rd tome. As he is stopped by the vines, I use a Thorn Wake on him to apply the 20% increased damage. Unfortunately, that pushed the boss in the right wall and it got stuck there, not moving or attacking me anymore. As it is out of my reach, I tried completing the map only to be greeted by a boss firewall before the ending.
Console logs (it was the last game played):
console-2021-06-07-13.12.19-7643768b-d72c-4ed4-89ca-706927ee734b.log (864.1 KB)