I believe this behavior occurred in prior iterations of Rule Machine and Hubitat, but it seems that when creating new rules with the Rule Machine, the process does not continue (spinning wheel upper right, Done button grayed out) unless you press Tab or click on the screen.
For example, if you go to make a new rule, you are presented with a box to type the new rule name into, but the rest of the screen is blank and the Remove/Done buttons are grayed out until you tab out of that name field or click somewhere on the screen.
I don't make rules that often, and I periodically forget this step is required, and just wonder when the spinning wheel will stop spinning.
So my feature request is that instead of the spinning wheel, simply enable the rest of the screen and the Remove/Done buttons after the first keypress in the Name field (e.g., if you are typing "New Rule", the "Done" button is enabled after the N is pressed). So this isn't jarring to the user, I would recommend presenting the whole screen (not just the Remove/Done buttons) initially but graying them out/disabling them, and then just enabling them after this first keypress in the Name field.
I get there is probably some AJAXy stuff on the backend where it wants you to tab away so it knows you are done so it can save the field in the database. However, I think this would be more intuitive to just do this save upon press of the first letter in the field, and then when someone clicks Done, just save any "Dirty" fields at that time.