Hello, I’m unfamiliar with this on Survival, as I’m not really experienced with it.
What I’d suggest, is to file a support ticket
here, and explain the situation and include the screenshots. It may be a bug, like you said so when filing it, I’d suggest putting it under the ‘Report a Bug’ department. Hopefully this gets resolved soon, the only explanations I can think of are it could be something to do with the Minecraft version you’re in, or it is just a server-side bug.
Here’s the link in-full to the support section, just incase the hyperlink doesn’t work for whatever reason.
https://forums.manacube.com/support/