Our game server began suffering an unpleasant amount of lag after updating to 1.9.4. Earlier, @hclewk pushed a newer build of 1.9.4 from Spigot in hopes of solving this problem.
Our goal is to stay updated on Minecraft versions as they roll out, however, if the problem persists, we have no problem with rolling back to 1.9.3..
Edit: Server TPS looks normal again. Please PM me if you are still experiencing connection issues. (5/12 @11:22PM CST)