A previous patch made it so obstacles inside a boss arena would be destroyed, and kept respawning.
This patch makes it so obstacles are not destroyed, only disabled, fixing the issue.
Patch 1.1.4
Source: Steam Community (opens in a new tab)
Build and release context
Steam update times within 24 hours of this post. Matching dates do not confirm which build it describes.
Build 14388489 · public branch
Steam updated · First observed