Steps to replicate the issue (include links if applicable):

• Enter a category name in the category field
• Using the keyboard down arrow select one of the relevant parent category
• Press enter to navigate to its sub categories
• Using the keyboard down arrow select the parent category
• Press enter on keyboard to add parent category to the field

What happens?:

• sometimes the parent category does not get added to the field when using keyboard
• sometimes it gets added if you select it again using keyboard
• sometimes it works right away

What should have happened instead?:

• the parent category should always get added to the field when using keyboard

Software version (on Special:Version page; skip for WMF-hosted wikis like Wikipedia):
Upload wizard in production

Other information (browser name/version, screenshots, etc.):
On Desktop. Happens on google chrome, safari. Have not tested on other browsers yet.