Your Windows build number: (Type ver at a Windows Command Prompt)
Microsoft Windows [Version 10.0.18342.8]
(But this happens on all versions of Windows since at least Windows 7.)

What you're doing and what's happening: (Copy & paste specific commands and their output, or include screen shots)
In the cmd.exe console, set to code page 65001, type a large UTF-8 file containing hundreds of short lines with just the characters "ü€ü€ü€ü€ü€"

What's wrong / what should be happening instead:
95% of the lines are displayed correctly, but about 5% contain spurious characters. Ex: "ü���ü€ü€ü€ü€"
This happens with any application, not just cmd.exe's built-in TYPE command. So I suspect this is a bug in the UTF-8 to Unicode conversion routine in the console output handler.
For more details, and files and scripts for reproducing it, see the discussion thread on this forum: https://www.dostips.com/forum/viewtopic.php?f=3&t=9017