Input field for IP address resets upon going to fullscreen

I start Minecraft, it loads in and while still in the default screen size, I click add a server and begin typing in an IP address to add. I then click the little expand icon to change the screen size to fullscreen, and the field for adding the IP address is reset.

What I expected to happen was...:
When I changed the screen size, the field should of stayed the same and not reset.

What actually happened was...:
Instead it reset and the field was empty.

Steps to Reproduce:
1. Start minecraft, keep it on the default start screen size.
2. Click "add a server"
3. Type in an IP address and before clicking finish, change the screen size to fullscreen.

Video: https://youtu.be/Q8wY3lWQWF0