The beam from a beacon only displays if you are looking at the beacon block itself. It's very easy to reproduce this by powering a beacon on creative mode and flying upward, then looking up.
Comments 2
Cleaning up old tickets: This ticket had been set to 'Awaiting Response', but has not received a response from the reporter (~3 months+) so is being closed as Incomplete. If you feel this is still a valid issue then please comment, or create a new ticket following the Issue Guidelines which includes steps to reproduce the problem.
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Is this still an issue in 1.16.201?