I had (have?) the same issue. Posting comments there okay, but not top-level posts from either hive.blog or peakd.com

But posting from the Actifit dApp results in a post displaying on both chains. @bryan-imhoff was having Missing Posting Authority trouble too but said it got better late in the day ( I have not tried posting since then). Related or not, both of us used iOS.

I did get a tiny test post to work from a Windows machine, but a second “real” post from the same computer failed.

………………

Edited update: I just posted from peakd.com and it worked fine.