I'm being driven up a wall by a Heisenbug I have with the #GoActivityPub HTTP-Signature plumbing.
On a multi tenant #ActivityPub service where I have two Actors, one of them can interact with the Fediverse at large without any issue, while the other gets HTTP Signature validation errors for every request.
There's no suspicious difference between the two private/public key pairs of the two actors. (I've even tried using the same key pair)
Sigh...