I get it often because I browse the web from wireguard.krowverse.services (rip=126.96.36.199), which is a Digital Ocean IP (AS14061).
VPS infrastructure is used often by attackers and some websites choose to proactively block them.
Both my VPS providers are dealing with spam, so falling back to my ISP would be a solution, although it would reveal my true location and traffic.
You will have to decide if staying on Pixelfed is worth it.
Personally, websites who block ASNs instead of netblocks don't deserve my business.
This Mastodon instance is for people interested in technology. Discussions aren't limited to technology, because tech folks shouldn't be limited to technology either!