Rhyain

Hiya, sorry if I used the wrong section for this - my friends can no longer break/place blocks, I have NO plugins and I'm unsure if this is a new update. This happened yesterday as well when we created a new server, I do not want to OP them because I do trust them but some of them I don't and they might use their op for their own personal benefits which I don't want. We've been playing this server for a few weeks now so I'm unsure why it isn't working all of a sudden, if anyone could help that'd be great. And once again I'm sorry if I posted this in the wrong section of the forum, please redirect me to the right section if I've placed it into the wrong one as well as answering my question! Kind Regards, Minecraft - Rhyain