This is working as intended.
I think you should report it in the Launcher bug page (https://bugs.mojang.com/projects/MCL/issues/])
Sorry, but I don't know how long it will take to fix. I'm not with Mojang, so I don't know anything about that process.
Please include screenshots of the issue.
If that doesn't work, try pressing Fn + F1.
Your game is modified (the star in the top bar). If you can re-create the bug in a vanilla environment (no mods, datapacks, or plugins), feel free to create a new ticket.
Are you on Bedrock edition or Java edition? If you are on Bedrock edition, please create a ticket on https://bugs.mojang.com/projects/MCPE/issues, but if you are on Java edition, then this is a new bug.
This is a problem with your account, not a bug, so please go to the Minecraft Help Center https://help.minecraft.net/hc/en-us/requests/new for help with this.
If you can reproduce the glitch in vanilla Minecraft, feel free to create a new ticket.
Could you describe the problem?
Were you using mods of any sort (Optifine, Forge, etc.)?
Please do not re-upload your bugs.
Could you include an image or video of the issue with the F3 debug screen up? (Press F3, or Fn+F3)
Could you record a video of this happening with the F3 debug screen?
Is this just with cobbled deepslate?
Then I don't know, sorry.
Were you on multiplayer?
Could you add a short video showing the bug?