The simplest workaround is to simply double click on the PIO Home tab - before that, I used to close and re-open PIO Home. This is before I found out that the underlying issue is that keyboard focus has been lost, as between opening PIO Home, and trying to enter some text, you’ve clicked on some element of VSCode, and due to a bug in VSCode, it doesn’t return keyboard focus to WebViewPanel’s when they are clicked on. 
A simple experiment to demonstrate… Have a VSCode terminal panel open… i.e. the PIO Terminal… open PIO home, scroll down ‘Recent Projects’ and enter anything… just some text… ddd will do… then click on the terminal… when you do ddd, the terminal gets the characters you type… then click on the ‘Recent Projects’ input box again (which even lights up as you move over it)… and when you type ddd… it appears in the terminal… really helpful, that is!.. double click on the PIO Home tab up the top, and when you click on the input box… keyboard input finally works again… yay!