This is not a problem! You may have forgotten to flick the ‘toggle’ to share, on the pop up when you initially copied the link.
To check this, go to your Team Board.
Click the 'share' button on the right hand side of the top white banner.
Ensure you've moved the toggle to 'Enable sharing on this team'
Then, copy the link.
If you are still having problems, connect with the Beamible support crew via the chat function in the bottom right-hand corner of the app.