FWIW I also have a filter up for "@twitter.com" which is gonna filter this out probably which is fine. But it helps me both avoid cross-posted RTs and when you're posting in a way which makes it clear you're interested in engaging folks on Twitter.
So if you're over here and trying to figure out how to avoid it without blocking folks, that's another way!
Or "RT @"
Use your instance's URL /filters to get there if you're not yet familiar!