Image is from a post in this community using this account. All comments on all posts when using my piefed.social account have a locked symbol next to them and give this "Locked by moderators" message if I try to reply. Replying to the post itself is fine and works without issue though. If I look at the same post from an account on another instance, I can see that the comments are not locked and can reply to them. Not sure if this is an issue with my account specifically or with Boost/piefed interaction, but it only started happening yesterday.
The field for locked comments has changed in the API. Updating the app to reflect this.