I know you all are dealing with DDoS and how that goes. I run DDoS mitigation for some juicy targets and do a lot of on-call response to handle those issues, so believe me when I say I know what you are dealing with.
However, that being said, it appears you are blocking tor exit nodes with a 403, likely at your web termination point (nginx, apache, whatever), and this kind of sucks.
I get that tor can bring some attacks, and I fully support a modulated response to those attacks, preferably one with a reasonable time decay, but please don’t just block all of tor
Alternatively, be one of the cool kids, and setup an onion service for lemmy.world!
Typical infosec fallacy: letting the perfect be the enemy of the good.