Hello,
There has been some updates to Windows regarding this display bug. I would like to stress the need to check if your system has been fully updated, and also if you have manually restarted the computer. In many cases, even after applying updates, the computer will be shutdown which, since windows 10 it will use the Fast Startup mode meaning that the system hasn't rebooted, but instead entered a similar state to hibernation which will not reload the updated components.
On the other hand, one quick fix for the issue would be to configure the taaskbar as "Auto-Hide", and once the menu is popped, if you move the cursor out of the taskbar area, you should see the whole contextual menu.
Other option could be that you are using a lower screen resolution. I would recommend also to increase the resolution through the Windows Display Options.
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