They have not yet updated the bug reports website to handle Bedrock reports, but you can still report them anyway in the "Minecraft Bug Reports" tab. For the "Which Minecraft version were you using?" just put 1.13, but in the "Where does the bug occur?" or "Description of the bug" box explain that it is on the Bedrock server. I'm unsure if your prefix bug is still an issue, but if it is I recommend reporting it.Also, Bedrock reports isn't visible in bug reports website.