Seems to be some kind of nasty block-evading system operating an instance at:
activitypub-proxy.cf
(It's listed at https://fedidb.org/software/mastodon)
The proxy's domain redirects to installation instructions. To quote them:
"A simple proxy for ActivityPub that lets you circumvent blocks by masquerading as another domain name..."
"...say you want to follow (someone) but the woke administrator has blocked you..."
It is deliberately avoiding blocks and helping others to do so too.
#FediBlock