Keyboard up/down arrows inconsistent behavior with repo selector

Describe the bug

In the repository selector, the behavior of the up and down keyboard keys is inconsistent. It would be great if the down arrow would consistently allow the user to select a matching repository.

Version & OS

2.6.1, Windows 10 x64 latest

Steps to reproduce the behavior

1. Configure at least a few repos in GitHub Desktop.
2. Click the repo selector in the top left corner (or CTRL+T) and type any text that will match some repos - I typed nycdo in my screenshot, but it doesn’t seem to matter.
3. You will see a list of matching repositories that GitHub Desktop knows about.
4. Press the down arrow key on the keyboard with the repository search box still focused. Sometimes this will navigate down to the first matching repository. Often it will not.
5. Press the up arrow key on the keyboard with the repository search box still focused; This seems to always navigate down to the bottom match (it loops around to the bottom from the top).
6. Once having “unstuck” the text box, you should be able to navigate up and down, including into and out of the repository search box with the up and down arrow keys freely.

Expected behavior

The down arrow should always pick the first selection in the results in the repository picker.

Actual behavior

Often, pressing the down arrow key does nothing. Unsticking it by using the up arrow key appears to fix it, and then down arrow will work as expected.

Screenshots

[nycdotnet]

I have also observed the behavior in @filiptronicek ‘s video where Desktop “fights” against your down arrows and will go back up on its own, though this is somewhat rare. Not sure if it’s the same underlying cause. Thanks.

[filiptronicek]

I have also found, that sometimes it gets bugged and when trying to navigate down, it just doesn’t sometimes let me go down (in this video, I never pressed the arrow up, just the arrow down key)

https://user-images.githubusercontent.com/29888641/106390201-84b54700-63e7-11eb-8f21-3c9370dff991.mp4

I am on 2.6.3-beta1 (Win10), but this has been happening for a while now.