Describe the bug
I was able to issue a few commands, then cmd + up before the first command was issued. It seems to allow for two blocks before the top-most command (I had to issue two cmd + down to get the selected block back on-screen).

To Reproduce

1. Open new tab
2. Send a few commands (I issued a couple clear commands).
3. cmd + up repeatedly.

Expected behavior
It stops at the top-most block.

Desktop (please complete the following information):
MacOS 11.2.3