This will be because the plugin has a timer that waits after a keystroke for the user to type a word, and that setting is too fast for your use. One thing you can try is to disable the Update the Search Form on user interaction and see if that helps, or is the form actually submitting?

This sensitivity setting is currently fix, but I am hoping that V3 of our plugin will make this an option you can set.

Also, after a form has reset, the cursor goes back to the start of the text. This is annoying but it is a browser/HTML standard. There are many threads about this on stackexchange, such as this:

https://stackoverflow.com/questions/511088/use-javascript-to-place-cursor-at-end-of-text-in-text-input-element

You might use javascript to attach an event like this to the text field.